Intelligent phototriggered nanoparticles induce a domino effect for multimodal tumor therapy.

Rationale: Integration of several monotherapies into a single nanosystem can produce remarkable synergistic antitumor effects compared with separate delivery of combination therapies. We developed near-infrared (NIR) light-triggered nanoparticles that induce a domino effect for multimodal tumor therapy. Methods: The designed intelligent phototriggered nanoparticles (IPNs) were composed of a copper sulfide-loaded upconversion nanoparticle core, a thermosensitive and photosensitive enaminitrile molecule (EM) organogel shell loaded with anticancer drugs, and a cancer cell membrane coating. Irradiation with an NIR laser activated a domino effect beginning with photothermal generation by copper sulfide for photothermal therapy that also resulted in phase transformation of the EM gel to release the anticancer drug. Meanwhile, the NIR light energy was converted to ultraviolet light by the upconversion core to excite the EM, which generated reactive oxygen species for photodynamic therapy. Results: IPNs achieved excellent antitumor effects in vitro and in vivo with little systemic toxicity, indicating that IPNs could serve as a safe and high-performance instrument for synergetic antitumor therapy. Conclusion: This intelligent drug delivery system induced a chain reaction generating multiple antitumor therapies after a single stimulus.

Water-Soluble Organic Nanoparticles with Programable Intermolecular Charge Transfer for NIR-II Photothermal Anti-Bacterial Therapy.

Extensive recent efforts have been put on the design of high-performance organic near-infrared (NIR) photothermal agents (PTAs), especially over NIR-II bio-window (1000-1350 nm). So far, the development is mainly limited by the rarity of molecules with good NIR-II response. Here, we report organic nanoparticles of intermolecular charge-transfer complexes (CTCs) with easily programmable optical absorption. By employing different common donor and acceptor molecules to form CTC nanoparticles (CT NPs), absorption peaks of CT NPs can be controllably tuned from the NIR-I to NIR-II region. Notably, CT NPs formed with perylene and TCNQ have a considerably red-shifted absorption peak at 1040 nm and achieves a good photothermal conversion efficiency of 42 % under 1064 nm excitation. These nanoparticles were used for antibacterial application with effective activity towards both Gram-negative and Gram-positive bacteria. This work opens a new avenue into the development of efficient PTAs.

A novel PVDF-TiO2@g-C3N4 composite electrospun fiber for efficient photocatalytic degradation of tetracycline under visible light irradiation.

A novel composite electrospun fiber with high photocatalytic efficiency, good stability, strong hydrophobicity, good pollution resistance, and easy separation and recovery was synthesized. The TiO2@g-C3N4 (TCN) with special core-shell structure (5-10 nm shell) facilitated the separation of photogenerated electron-holes and had high photocatalytic performance. The poly (vinylidene fluoride) (PVDF) electrospun fiber immobilized with TCN was successfully fabricated (PVDF-TCN) with uniform distribution and size of nanofibers by using electrospinning, which was used for degrading tetracycline under visible-light irradiation (> 400 nm). A special rougher surface of electrospun fiber obtained by washing of sacrificial PVP increased the specific surface area, which became more conducive to the adhesion of the catalyst. The water contact angle and FTIR results demonstrated that the electrospun fiber became extremely hydrophilic after adding TCN catalyst, which could effectively mitigate the fiber pollution. The PVDF-TCN-0.2g electrospun fiber exhibited excellent photocatalytic performance and the degradation efficiency of tetracycline was up to 97% in 300 min under visible-light irradiation. The mechanism of PVDF-TCN electrospun fiber degradation of tetracycline in the photocatalytic process was also proposed. In addition, the PVDF-TCN-0.2g exhibited a stable activity after 4 cycles experiments since the degradation efficiency remained about 90%. Therefore, we believed this study provided a new strategy in catalyst immobilization and wastewater treatment.

Near-infrared emission tracks inter-individual variability of carboxylesterase-2 via a novel molecular substrate.

A low-molecular-weight molecule (4-(2-(3-(dicyanomethyl)-5,5-dimethylcyclohex-1-en-1-yl)vinyl)phenyl-benzoate, DDPB) has been developed. The organic framework possesses very weak fluorescence . The feasibility of the signal transduction has been performed via fluorometric titrations in solution. DDPB gives rise to responses to carboxylesterase 2 (CES2) based on "off-on" responses. The red emission at 670 nm has been derived from the enzyme-induced hydrolysis of ester linkages, thus suppressing the intramolecular charge transfer (ICT) effect and thereby generating the fluorescent segment. The optical excitation window for this probe is extended to the visible light range (λex = 516 nm), and it will induce less harmful influence on biological substances. The detection limit for the measurement of CES2 concentration is as low as 2.33 mU/mL. The conventional studies concerning the activation process are generally performed within only a single liveing cell system. In this study, it is the first time that expression of carboxylesterase 2 in five kinds of cell lines (HeLa > C1498 > active T cell > Jurkat > unactive T cell) has been clarified by flow cytometry, Western blotting, and confocal microscopy analysis. The elucidation of CES2 and its variability in a variety of cells will open new ways for drug metabolism and disease prevention. Graphical abstract We reported a new "substrate-mediated light-on" strategy based on an ester bond cleavage reaction. Most of prepared nanomaterials and organic fluorophores possessed short wavelength emissions in the blue or green region which will not be difficult for cellular imaging. In this study, a novel functional molecule (DDPB) was considered as the substrate for CES2 and the optical "off-on" response was realized. DDPB was cell permeable and possessed very low cytotoxicity. Moreover, the identification of CES2 and their subtle changes in five different cells afforded the sequence for carboxylesterase-2 as Hela > C1498 > Active T cell > Jurkat > Unactive T cell. Inhibition studies showed that the hydrolysis of DDPB was effectively suppressed by bis-p-nitrophenyl phosphate and the cellular tracking results firmly supported this point. To our knowledge, the inter-individual variability for the CES2 expressions in five different cell lines has never been reported via the substrate induced optical changes.

Aptamer-based photoelectrochemical assay for the determination of MCF-7.

In this work, an aptamer-based photoelectrochemical (PEC) assay is reported for the determination of MCF-7 breast cancer cells using hexagonal carbon nitride tubes (HCNTs) as photoactive material. The aptamer immobilized on the HCNT surface can specifically bind with mucin 1 protein (MUC1) that is overexpressed on the surface of MCF-7 cell. Thus, the PEC assay has high specificity for the determination of MCF-7. The determination of MCF-7 is due to the binding of MCF-7 onto HCNT that suppressed the photocurrent intensity. The PEC assay displays good performances for MCF-7 determination with a linear range from 1 × 102 to 1 × 105 cell mL-1 and limit of detection down to 17 cells mL-1. Meanwhile, the PEC assay can distinguish MCF-7 from normal cells in blood samples, which may have potential applications in cancer diagnostics and therapeutics.

A novel synthetic carbon and oxygen doped stalactite-like g-C3N4 for broad-spectrum-driven indometacin degradation.

Achieving efficient solar utilization is a primary goal in the field of photocatalytic degradation of PPCPs. For this study, a broad-spectrum carbon and oxygen doped, porous g-C3N4 (COCN) was synthesized via a simple co-pyrolysis of dicyandiamide and methylamine hydroiodide (CH5N·HI). The 0.3COCN demonstrated an excellent photocatalytic degradation of indometacin (IDM), which was 5.9 times higher than bulk g-C3N4. The enhanced photocatalytic activity could be ascribed to the broad-spectrum utilization of solar light and improved charge separation efficiency. Reactive species (RSs) scavenging experiments have shown that O2·- and 1O2 were the dominant active species. Further, the 0.3COCN exhibits excellent yield of hydroxyl radicals which was confirmed by electron spin resonance (ESR) spectra. Meanwhile, the degradation pathways of IDM were proposed according the HRAM LC-MS/MS and total organic carbon (TOC). This research provided a new strategy for a broad-spectrum photocatalyst, and a promising strategy for environmental remediation.

Nitrofurazone degradation in the self-biased bio-photoelectrochemical system: g-C3N4/CdS photocathode characterization, degradation performance, mechanism and pathways.

In this study, a self-biased bio-photoelectrochemical system (SB-BPES) was constructed using a bioanode and the g-C3N4/CdS heterojunction photocathode for nitrofurazone (NFZ) degradation under solar irradiation. The physio-chemical properties and optical performance of photocatalysts were characterized, and photo-electrochemical properties of various photocathodes were analyzed. Results showed that g-C3N4/CdS exhibited the broadest visible light absorption range (to 594 nm) and the most efficient e--h+ separation; and its corresponding photocathode showed the highest photocurrent (9.8 µA), and the lowest charge transfer resistance (5.43 ☓ 103 Ω). In the solar-illuminated SB-BPES with g-C3N4/CdS photocathode, about 80% of NFZ removal rate was achieved within 10 h. More importantly, TOC removal of 62.6% was achieved in 24 h, which was 1.8 times of that from the open circuit SB-BPES, and 4.3 folds of that from microbial degradation; also, about 1.5 times of those from SB-BPES with g-C3N4 and CdS photocathodes. Besides, reproducible current generations (∼1.0 mA) were produced. These verified that it was a self-sustained system for spontaneously pollutants degradation and electricity generation. Moreover, possible degradation mechanism and pathways were proposed according to the identified intermediates. This study provides inspiration for synchronic improving refractory organics degradation and net energy recovery.

Influence of photo-initiators in the preparation of methacrylate monoliths into poly(ethylene-co-tetrafluoroethylene) tubing for microbore HPLC.

In this study, poly(butyl methacrylate-co-ethyleneglycol dimethacrylate) polymeric monoliths were in situ developed within 0.75 mm i.d. poly(ethylene-co-tetrafluoroethylene) (ETFE) tubing by UV polymerization via three different free-radical initiators (α,α'-azobisisobutyronitrile (AIBN), 2,2-dimethoxy-2-phenylacetophenone (DMPA) and 2-methyl-4'-(methylthio)-2-morpholinopropiophenone (MTMPP). The influence of the nature of each photo-initiator and irradiation time on the morphological features of the polymer was investigated by scanning electron microscopy, and the chromatographic properties of the resulting microbore columns were evaluated using alkyl benzenes as test substances. The beds photo-initiated with MTMPP gave the best performance (minimum plate heights of 38 µm for alkyl benzenes) and exhibited a satisfactory reproducibility in the chromatographic parameters (RSD < 11%). These monolithic columns were also successfully applied to the separation of phenylurea herbicides, proteins and a tryptic digest of ß-casein.

Anchoring single-unit-cell defect-rich bismuth molybdate layers on ultrathin carbon nitride nanosheet with boosted charge transfer for efficient photocatalytic ciprofloxacin degradation.

Photocatalysis technology is regarded as a promising way for environmental remediation, but rationally designing photocatalysis system with high-speed interfacial charge transfer, sufficient photoabsorption and surface reactive sites is still a challenge. In this study, anchoring single-unit-cell defective Bi2MoO6 on ultrathin g-C3N4 to form 2D/2D heterostructure system is a triple-purpose strategy for high-performance photocatalysis. The defect structure broadens photo-responsive range. The large intimate contact interface area between two monomers promotes charges carrier transfer. The enhanced specific surface area exposes more reactive sites for mass transfer and catalytic reaction. As a result, the obtained heterostructure displays excellent photocatalytic performance for ciprofloxacin (CIP) (0.0126 min-1), which is 3.32 and 2.93 folds higher than Bi2MoO6 and g-C3N4. In addition, this heterostructure retains high-performance for actual wastewaters treatment, and it displays strong mineralization ability. And this heterojunction also exhibits excellent photostability based on cyclic experiment. Mechanism exploration reveals that hole, superoxide radical, and hydroxyl radical are chief reactive species toward CIP degradation, thereby a Z-scheme charge carrier transfer channel is proposed. In addition, the intermediates and degradation pathways of CIP are tracked by liquid chromatography-triple quadrupole tandem mass spectrometry (LCMS/MS) and three-dimensional excitation-emission matrix fluorescence spectroscopy (3D EEMs). This study paves new way to design and construct atomic level 2D/2D heterojunction system for environment remediation.

In suit inducing electron-donating and electron-withdrawing groups in carbon nitride by one-step NH4Cl-assisted route: A strategy for high solar hydrogen production efficiency.

Owing to insufficient active sites, strongly bound excitons and insufficient optical absorption, polymer semiconductors have only shown mild activity as potential candidates for photocatalysis. A g-C3N4 with improved optical absorption capacity, charge transfer performance and porosity was successfully prepared by a one-step NH4Cl-assisted route. Interaction of melamine with NH4Cl preparation of Porous g-C3N4(CN-xy) with active functional groups modified pore wall shown to result in highly crystalline species with a maximum π-π layer stacking distance of heptazine units of 0.321 nm, decreases the optical band gap from 2.80 to 2.13 eV and maximum surface area reached 56.485 m2 g-1. The balanced improvement of the multiple defects of g-C3N4 makes the photocatalytic degradation of RhB and the photocatalytic hydrogen production efficiency 4 and 5 times higher than the pristine g-C3N4, respectively.

A Sunlight Powered Portable Photoelectrochemical Biosensor Based on a Potentiometric Resolve Ratiometric Principle.

As a new analysis tool, photoelectrochemical (PEC) biosensors have been widely studied in recent years. However, common PEC biosensors usually require a highly stable light source to excite the electrical signal and an electrochemical workstation to collect and process the signal data, which limited the development of portable PEC devices. Herein, we propose the design of a sunlight powered portable PEC biosensor that uses sunlight as the light source. The sunlight intensity changes over time and weather and results in varied background PEC currents. To eliminate the interference caused by unstable excitation light, the potentiometric resolve ratiometric principle was introduced. Coupled with a miniature electrochemical workstation and a laptop, a sensitive and portable PEC sensing platform was successfully developed. The detection may be achieved under the irradiation of sunlight and will no longer need an extra light source. In a proof of concept experiment, this platform was successfully applied in aflatoxin B1 analysis, which was promising in the development of portable biosensors.

A ratiometric photoelectrochemical immunosensor based on g-C3N4@TiO2 NTs amplified by signal antibodies-Co3O4 nanoparticle conjugates.

Herein, we report a ratiometric photoelectrochemical (PEC) immunosensor coupled with secondary antibodies-Co3O4 nanoparticle conjugates (Ab2-Co3O4 NPs) for signal amplification. The Ab1-g-C3N4@TiO2 NTs and BSA-g-C3N4@TiO2 NTs act as the sensing and reference photoelectrodes, where Ab1, BSA and TiO2 NTs are the capture antibodies, bovine serum albumin and TiO2 nanotube arrays, respectively. In the presence of target Ag, the sensing PEC photocurrent decreases due to the steric hindrance of Ab1 molecules, which increases the inner resistance of the photoelectrode. The signal-off response is enhanced further using Ab2-Co3O4 NP conjugates due to their steric hindrance effect and the consumption of electron donors by the Co3O4 NPs. Furthermore, the performance of the ratiometric PEC platform is tested using alpha-fetoprotein (AFP) as a model antigen. Under the optimal conditions, the concentration of AFP is detected in the range of 0.4 pg mL-1 to 40 ng mL-1 with a detection limit of 0.2 pg mL-1. This ratiometric strategy is beneficial to improve the reliability and anti-interference ability of PEC immunosensors.

Honeycomb-like carbon nitride through supramolecular preorganization of monomers for high photocatalytic performance under visible light irradiation.

A metal-free modified carbon nitride MCU(DMSO)-C3N4 (3:3:1) with a honeycomb-like morphology was prepared via firstly introducing cyanuric acid and urea into melamine in dimethyl sulfoxide (DMSO) as the precursor for the MCU-C3N4. A variety of characterization methods, including XRD, XPS, FT-IR, SEM, TEM, UV-vis, photoluminescence (PL), and photocurrent generation, were applied to investigate the structure, morphology, optical, and photoelectrochemical properties of the g-C3N4 and MCU-C3N4 (3:3:1). Rhodamine B (RhB), methylene blue (MB), and bisphenol A (BPA) were selected as target pollutants to evaluate photocatalytic activity of the MCU-C3N4 (3:3:1) under visible light irradiation. MCU-C3N4 (3:3:1) exhibits significantly enhanced photocatalytic activity compared with g-C3N4, where 99.49% RhB is removed within 40min, 97.7% MB is removed within 80 min, and 84.37% BPA is removed within 90 min. The improved photodegradation efficiency was mainly due to the larger surface area, the stronger REDOX ability, and the increased separation efficiency of photogenerated electron-hole pairs. The active radical trapping experiments and electron spin resonance tests indicated that h+ and O2- radicals were the dominant active species whereas OH radicals could be a minor factor. A possible photocatalytic mechanism is proposed. This strategy here provides an ideal platform for the design of photocatalysts with large surface area and high porosity for various pollutant controlling applications.

Boron- and phenyl-codoped graphitic carbon nitride with greatly enhanced light responsive range for photocatalytic disinfection.

The development of metal-free photocatalyst to make maximum use of the solar energy for photocatalytic disinfection is highly desired. Herein, boron-and phenyl-codoped graphitic carbon nitride was prepared by thermal polycondensation of cyanamide with 3-aminobenzeneboronic acid and applied as photocatalyst to inactivate Escherichia coli (E. coli). The photocatalysts exhibited the enhanced light responsive range over ultraviolet to near infrared light and 99.9% bacteria could be inactivated within 3 h with a low concentration of photocatalyst under the irradiation of simulated solar light. The disinfection mechanism was studied by scavenger experiments, indicating H2O2 was the main reactive species for the inactivation of bacteria. Finally, the photocatalyst was deposited on the surface of solid material and also exhibited strong disinfection performance. Taking advantage of excellent disinfection activity and low cytotoxicity, the photocatalyst showed a promising application in solar-driven photocatalytic disinfection in public place.

Green synthesis of luminescent graphitic carbon nitride quantum dots from human urine and its bioimaging application.

A hydrothermal synthetic approach is developed for the preparation of graphitic carbon nitride quantum dots (g-C3N4 QDs) from human urine. The reported synthetic method is green, simple, low-cost, less time-consuming, and can be used for the large-scale production of the g-C3N4 QDs. The as-prepared g-C3N4 QDs possess a high quantum yield of 15.7% by using quinine sulfate as a reference, and display excitation-wavelength dependent fluorescent emission. In addition, the g-C3N4 QDs exhibit high photostability, low cytotoxicity. and are successfully used as fluorescent probes for cell multicolor imaging. It is believed that the valuable nanomaterials, g-C3N4 QDs, which are transformed from the human bodily wastes, are promising in diverse chemical applications.

Ru(II) Polypyridyl Complexes Derived from Tetradentate Ancillary Ligands for Effective Photocaging.

Metal complexes have many proven applications in the caging and photochemical release of biologically active compounds. Photocaging groups derived from Ru(II) traditionally have been composed of ancillary ligands that are planar and bi- or tridentate, such as 2,2'-bipyridine (bpy), 2,2':6',2″-terpyridine (tpy), and 1,10-phenanthroline (phen). Complexes bearing ancillary ligands with denticities higher than three represent a new class of Ru(II)-based photocaging groups that are grossly underdeveloped. Because high-denticity ancillary ligands provide the ability to increase the structural rigidity and control the stereochemistry, our groups initiated a research program to explore the applications of such ligands in Ru(II)-based photocaging. Ru(TPA), bearing the tetradentate ancillary ligand tris(2-pyridylmethyl)amine (TPA), has been successfully utilized to effectively cage nitriles and aromatic heterocycles. Nitriles and aromatic heterocycles caged by the Ru(TPA) group show excellent stability in aqueous solutions in the dark, and the complexes can selectively release the caged molecules upon irradiation with light. Ru(TPA) is applicable as a photochemical agent to offer precise spatiotemporal control over biological activity without undesired toxicity. In addition, Ru(II) polypyridyl complexes with desired photochemical properties can be synthesized and identified by solid-phase synthesis, and the resulting complexes show properties to similar to those of complexes obtained by solution-phase synthesis. Density functional theory (DFT) calculations reveal that orbital mixing between the π* orbitals of the ancillary ligand and the Ru-N dσ* orbital is essential for ligand photodissociation in these complexes. Furthermore, the introduction of steric bulk enhances the photoliability of the caged molecules, validating that steric effects can largely influence the quantum efficiency of photoinduced ligand exchange in Ru(II) polypyridyl complexes. Recently, two new photocaging groups, Ru(cyTPA) and Ru(1-isocyTPQA), have been designed and synthesized for caging of nitriles and aromatic heterocycles, and these complexes exhibit unique photochemical properties distinct from those derived from Ru(TPA). Notably, the unusually greater quantum efficiency for the ligand exchange in [Ru(1-isocyTPQA)(MeCN)2](PF6)2, Φ400 = 0.033(3), uncovers a trans-type effect in the triplet metal-to-ligand charge transfer (3MLCT) state that enhances photoinduced ligand exchange in a new manner. DFT calculations and ultrafast transient spectroscopy reveal that the lowest-energy triplet state in [Ru(1-isocyTPQA)(MeCN)2](PF6)2 is a highly mixed 3MLCT/3ππ* excited state rather than a triplet metal-centered ligand-field (3LF) excited state; the latter is generally accepted for ligand photodissociation. In addition, Mulliken spin density calculations indicate that a majority of the spin density in [Ru(1-isocyTPQA)(MeCN)2](PF6)2 is localized on the isoquinoline arm, which is opposite to the cis MeCN, rather than on the ruthenium center. This significantly weakens the Ru-N6 ( cis MeCN) bond, which then promotes the ligand photodissociation. This newly discovered effect gives a clearer perception of the interplay between the 3MLCT and 3LF excited states of Ru(II) polypyridyl complexes, which may be useful in the design and applications of ruthenium complexes in the areas of photoactivated drug delivery and photosensitizers.

Molecular engineering of polymeric carbon nitride: advancing applications from photocatalysis to biosensing and more.

As a promising two-dimensional (2D) conjugated polymer, polymeric carbon nitride (CN) is attracting dramatically increasing interest due to its unusual properties, facile synthesis from abundant and inexpensive starting materials, and promising applications ranging from (photo)catalysis, and photoelectrochemistry, to biosensors. The polymeric feature and facile synthesis of CN allow easy engineering of its structure at the molecular level. For instance, the moderate reactivity of CN at the interface, together with the aromatic π-conjugated framework and intralayer hydrogen bonds, provides ample possibilities to control its molecular structure and properties to meet task-specific applications. This review summarizes and highlights a panorama of the latest advancements related to the design and construction of the molecular structure of CN, such as by doping and copolymerization, engineering of the polymerization degree, coordination interaction, covalent and noncovalent functionalization, and modulation of intralayer hydrogen bonding. Beyond photocatalysis, the emerging applications of CN are also briefly discussed with a special emphasis on sensing, bioimaging and biotherapy, smart responsive systems and photoelectrochemical devices. This review ends with perspectives on the challenges and future prospects of molecular engineering of CN.

Ru(ii) polypyridyl complexes as photocages for bioactive compounds containing nitriles and aromatic heterocycles.

Photocaging allows for precise spatiotemporal control over the release of biologically active compounds with light. Most photocaged molecules employ organic photolabile protecting groups; however, biologically active compounds often contain functionalities such as nitriles and aromatic heterocycles that cannot be caged with organic groups. Despite their prevalence, only a few studies have reported successful caging of nitriles and aromatic heterocycles. Recently, Ru(ii)-based photocaging has emerged as a powerful method for the release of bioactive molecules containing these functional groups, in many cases providing high levels of spatial and temporal control over biological activity. This Feature Article discusses recent developments in applying Ru(ii)-based photocaging towards biological problems. Our groups designed and synthesized Ru(ii)-based platforms for the photoinduced delivery of cysteine protease and cytochrome P450 inhibitors in order to achieve selective control over enzyme inhibition. We also reported Ru(ii) photocaging groups derived from higher-denticity ancillary ligands that possess photophysical and photochemical properties distinct from more traditional Ru(ii)-based caging groups. In addition, for the first time, we are able to rapidly synthesize and screen Ru(ii) polypyridyl complexes that elicit desired properties by solid-phase synthesis. Finally, our work also defined steric and orbital mixing effects that are important factors in controlling photoinduced ligand exchange.

NiS and MoS2 nanosheet co-modified graphitic C3N4 ternary heterostructure for high efficient visible light photodegradation of antibiotic.

The development of efficient solar driven catalytic system for the degradation of antibiotics has become increasingly important in environmental protection and remediation. Non-noble-metal NiS and MoS2 nanosheet co-modified graphitic C3N4 ternary heterostructure has been synthesized via a facile combination of hydrothermal and ultrasound method, and the ternary heterostructure has been utilized for photocatalytic degradation of antibiotic agents. The antibiotics of ciprofloxacin (CIP) and tetracycline hydrochloride (TC) were photodegraded by the hybrid under the visible light. The optimal photodegradation rate of the ternary heterostructure reaches about 96% after 2h irradiation, which is 2.1 times higher than that of pure g-C3N4 for TC degradation. The photocatalytic degradation rates of the ternary heterostructure for both CIP and TC obey the pseudo-first-order kinetic model. The enhanced visible light adsorption and charge separation efficiency contribute to the photocatalytic performance of the ternary heterostructure. This work provides new insights and pathways by which efficient degradation of antibiotics can be achieved and will stimulate further studies in this important field.

Construction of plasmonic Ag modified phosphorous-doped ultrathin g-C3N4 nanosheets/BiVO4 photocatalyst with enhanced visible-near-infrared response ability for ciprofloxacin degradation.

To realize the full utilization of solar energy, the design of highly efficient photocatalyst with improved visible-near-infrared photocatalysis performance has attracted great attentions for environment pollutant removal. In this work, we rationally employed the surface plasmon resonance effect of metallic Ag in the phosphorus doped ultrathin g-C3N4 nanosheets (PCNS) and BiVO4 composites to construct a ternary Ag@PCNS/BiVO4 photocatalyst. It was applied for the photodegradation of ciprofloxacin (CIP), exhibiting 92.6% removal efficiency under visible light irradiation (λ>420nm) for 10mg/L CIP, and presenting enhanced photocatalytic ability than that of single component or binary nanocomposites under near-infrared light irradiation (λ>760nm). The improved photocatalytic activity of the prepared Ag@PCNS/BiVO4 nanocomposite can be attributed to the synergistic effect among the PCNS, BiVO4 and Ag, which not only improves the visible light response ability and hinders the recombination efficiency of the photogenerated electrons and holes, but also retains the strong the redox ability of the photogenerated charges. According to the trapping experiment and ESR measurements results, OH, h+ and O2- all participated in the photocatalytic degradation process. Considering the SPR effect of metallic Ag and the established local electric field around the interfaces, a dual Z-scheme electrons transfer mechanism was proposed.