Broad-spectrum hybrid-driven triple-interface Z-Scheme 1T/2H phase sailboat-like molybdenum disulfide (MoS2)/protonated N-defect nanoporous graphitic carbon nitride (g-C3N4) nanosheets piezo-photocatalyst: Superior degradation and hydrogen evolution.

Incorporating piezo-response into photocatalysis holds great promise for eco-friendly strategies in environmental remediation and sustainable energy conversion. Herein, flexible N-defect nanoporous g-C3N4 nanosheets (NPCNs) was prepared via one-step method, then whose surface was protonated. And existed dense 1T/2H phase and vertical interfaces in non-layer-dependent-piezo-response sailboat-like-MoS2 (Sv-MS) formed by in-situ stresses during nucleation and growth by experiments and MD-simulations. Noble-metal-free Z-scheme PC/VM heterojunction with broad-spectrum absorption, enhanced piezo-response and intimate triple-interface was established by electrostatic self-assembly, performing efficient hybrid-driven piezo-photocatalysis. With a systematic modification of morphology, grain size, phase composition, and surface condition of the components, the optimal PC(3.6H)/VM(u2) exhibited high piezo-photocatalytic rates for degradation of organic dyes and antibiotic (RhB (0.565 min-1), MO (0.052 min-1), MB (1.557 min-1), TC (0.062 min-1)) and hydrogen evolution (3528 µmolg-1h-1) under visible-light and ultrasonic-wave, with maintenance under NIR-light (λmax = 1000 nm) attributed to up-conversion effect (RhB: 0.212 min-1, H2: 2355 µmolg-1h-1). Furthermore, the piezo-photocatalytic mechanism was proposed by experiments and DFT-calculations for effective triple-interface Z-Scheme charge migration. This work provides a rational protocol for constructing diverse-energy-triggered, multiple-interfaces and broad-solar-spectrum (UV-Vis-NIR) piezo-photocatalysts in degradation and hydrogen evolution.

Enhanced non-layer-dependent piezo-response in sailboat-like vertical molybdenum disulfide nanosheets for piezo-catalytic hydrogen evolution and dye degradation: Effect of microstructure and phase composition.

The piezo-response of two-dimensional molybdenum disulfide(MoS2) only exists at the edge of odd-number layers. It's crucial to design reasonable micro/nano-structures and construct tight interfaces to weaken layer-dependence, enhance energy harvesting, charge transfer and active sites exposure to improve piezoelectricity. The novel sailboat-like-vertical-MoS2-nanosheets(SVMS), in which abundant vertical MoS2 nanosheets(∼20 nm, 1-5 layers) are uniformly distributed on horizontal substrate of MoS2, with abundant vertical interfaces and controllable phase composition are prepared by facile method. The larger geometric-asymmetry enhances mechanical energy capture. Experiment and theory revealed the enhanced in-/out-of-plane polarization, higher piezo-response in multi-directions and abundant active edge sites of SVMS, thereby eliminating the layer-dependence and generating higher piezo-potential. Cooperating with the Mo-S bonds at vertical interfaces, free electrons-holes are efficiently separated and migrated. The piezo-degradation of Rhodamine B(RhB) and hydrogen evolution rate under ultrasonic/stirring are 0.16 min-1 and 1598 µmolg-1h-1 for SVMS(2H) with the highest piezo-response (under ultrasonic wave, stirring and water flow), which are over 1.6 and 3.1 times than few-layer MoS2 nanosheets. 94% RhB(500 mL) is degraded under water-flow(60 min). The mechanism was proposed. Overall, the design of SVMS with enhanced piezoelectricity was studied and modulated by regulating microstructure and phase composition, which has excellent application potential in fields of environment, energy and novel materials.

A superior ternary Z-scheme photocatalyst of Bi/Black Phosphorus nanosheets/P-doped BiOCl containing interfacial P-P bond and metallic mediator for H2O2 production and RhB degradation.

Photocatalytic performance is significantly influenced by the efficiency of photogenerated electron-hole pairs separation and transfer. In this paper, rational designed Z-scheme Bi/Black Phosphorus Nanosheets/P-doped BiOCl (Bi/BPNs/P-BiOCl) nanoflower photocatalyst was synthesized by a facile in-situ reduction process. The interfacial P-P bond between Black phosphorus nanosheets (BPNs) and P-doped BiOCl (P-BiOCl) was investigated by the XPS spectrum. The Bi/BPNs/P-BiOCl photocatalysts exhibited enhanced photocatalytic performance for H2O2 production and RhB degradation. The optimally modified photocatalyst (Bi/BPNs/P-BiOCl-20) showed an excellent photocatalytic H2O2 generation rate of 4.92 mM/h and RhB degradation rate of 0.1169 min-1 under simulated sunlight irradiation, which was 1.79 times and 1.25 times greater than the P-P bond free Bi/BPNs/BiOCl-20. The mechanism was investigated through charge transfer route, radical capture experiments, and band gap structure analysis, indicating that the formation of Z-scheme heterojunctions and interfacial P-P bond not only enhances the redox potential of the photocatalyst but also facilitates the separation and migration of photogenerated electrons-holes. This work might provide a promising strategy for constructing Z-scheme 2D composite photocatalysts combining interfacial heterojunction and elemental doping engineering for efficient photocatalytic H2O2 production and organic dye pollutant degradation.

Mechanochemical synthesis of unsymmetrical salens for the preparation of Co-salen complexes and their evaluation as catalysts for the synthesis of α-aryloxy alcohols via asymmetric phenolic kinetic resolution of terminal epoxides.

In this paper, we report the mechanochemical synthesis of unsymmetrical salens using grinding and ball milling technologies, respectively, both of which were afforded in good yield. The chelating effect of the unsymmetrical salens with zinc, copper, and cobalt was studied and the chiral Co-salen complex 2f was obtained in 98% yield. Hydrolytic kinetic resolution (HKR) of epichlorohydrin with water catalyzed by complex 2f (0.5 mol %) was explored and resulted in 98% ee, suggesting complex 2f could serve as an enantioselective catalyst for the asymmetric ring opening of terminal epoxides by phenols. A library of α-aryloxy alcohols 3 was thereafter synthesized in good yield and high ee using 2f via the phenolic KR of epichlorohydrin.

Bright Luminous and Stable CsPbBr3 @PS Microspheres Prepared via Facile Anti-solvent Method using CTAB as Double Modifier.

The past decade has witnessed the increasing interest in cesium lead halide perovskite quantum dots (PQDs) for their excellent optical properties with higher photoluminescence efficiency and tunable emission wavelengths widely applied in white LED, photovoltaic devices, etc. Here we report the preparation of CsPbBr3 PQDs by a facile anti-solvent method using conventional quaternary ammonium bromide (CTAB) as a double modifier-both proper alkyl group protection and bromine source donator. The as-formed PQDs are well-monodispersed cubes with a size of 10-15 nm and high photoluminescence quantum yield (PLQY) of up to 43 %. To enhance the stability of PQDs, CsPbBr3 @PS microspheres were formed by electrospraying process. The microspheres not only show excellent luminous properties, but exhibit much higher stability against air and UV light irradiation due to the super hydrophobic property of polystyrene.

One step fabrication of novel Ag-CdS@EP floating photocatalyst for efficient degradation of organic pollutants under visible light illumination.

In this paper, we present the fabrication of an expanded-perlite (EP)-based floating photocatalyst comprising CdS and Ag nanoparticles. In the Ag-CdS/EP nanocomposite, Ag-CdS was introduced as the photocatalytically active components and EP was employed as a low cost and sustainable support to reduce the problem of easy aggregation and improve the floating behavior of the designed catalyst. The Ag-CdS/EP photocatalyst was characterized via transmission electron microscopy (TEM), high-resolution transmission electron microscopy (HR-TEM), scanning electron microscopy (SEM), X-ray diffraction (XRD), UV-vis diffuse spectroscopy (UV-vis DRS), energy dispersive spectroscopy (EDS), X-ray photoelectron spectroscopy (XPS), and photoluminescence (PL) and photoelectrochemical measurements. The XRD and HR-TEM results confirmed the formation of cubic crystalline silver nanoparticles anchored on the surface of EP-immobilized hexagonal cubic CdS. The significantly enhanced photocatalytic activities of the Ag-CdS/EP nanocomposite with varying Ag contents were investigated for the degradation of rhodamine B (RhB) and phenol under visible light irradiation, and it was found that the photocatalytic reaction proceeds via first order kinetics. Furthermore, the desirable cycling ability (5 runs) of the Ag-CdS/EP photocatalyst indicates its promising stability and reusability. The designed novel photocatalyst also conforms to the development of green chemistry since no organic solvents were required.

Application of mercaptosuccinic acid capped CdTe quantum dots for latent fingermark development.

The aqueous synthesis of mercaptosuccinic acid (MSA) capped CdTe quantum dots (QDs) solution for quickly and sensitively developing latent fingermarks is described. The rapid growth mechanism of CdTe/MSA QDs, which depends on the molecule structure of MSA, is briefly discussed and compared with that of thioglycolic acid (TGA) and mercaptopropionic acid (MPA) capped CdTe QDs. Development of latent fingermarks with the synthesized CdTe/MSA QDs was faster and the ridge details were clearer compared with CdTe/TGA QDs. In addition, latent fingermarks developed with CdTe/MSA QDs showed less background and better contrast than that of gentian violet or rhodamine 6G. Latent fingermarks could be well developed on black tape, scotch tape, tinfoil, aluminum alloy, stainless steel as well as on the adhesive side of yellow tape, even when the latter were aged up to seven days. As immersion time greatly reduced to 10 s by using CdTe/MSA QDs, a preliminary result of latent fingermark development by spraying was presented also.

Preparation of mesoporous ferrisilicate with high content of framework iron by pH-modification method and its catalytic performance.

The mesoporous ferrisilicates (MFS) with high iron content were synthesized by pH-modification method, and the iron content could be up to 10.5 wt.% (Si/Fe=8). The pH was kept less than 2 at pre-hydrothermal synthesis step and was adjusted to 11 during hydrothermal step. The samples were characterized by XRD, HRTEM, N(2)-sorption, XRF, FTIR, DRUV-vis, Fe K-edge EXAFS, EPR, and DSC. The results suggested that the MFS materials were ordered 2D hexagonal mesophase of MCM-41, and the iron atoms were tetrahedral coordinated in the silica framework. This material could efficiently catalyze the hydroxylation of phenol in water medium using H(2)O(2) as an oxidant, and the phenol conversion could be up to 52% under the optimal experimental conditions.

Preparation of MCM-41 incorporated with lacunary Keggin polyoxometalate and its catalytic performance in esterification.

The ordered mesoporous MCM-41 materials incorporated with lacunary polyoxometalate were prepared via an original direct synthesis method. As the control, the samples with similar lacunary polyoxometalate loadings were also prepared by impregnation of MCM-41. The prepared samples were characterized by XRF, XRD, FT-IR, Raman spectra, HRTEM, SEM, N(2) adsorption isotherm, TG-DTA, and NH(3)-TPD technology. The results show that the lacunary polyoxometalate is better dispersed in the direct synthesized samples than in the impregnated samples, and its structure remains intact after formation of the materials. The catalytic performance of the materials was tested using the esterification of n-butanol with acetic acid. The direct synthesized samples display excellent catalytic performance and reusability, which is superior to the impregnated samples. Under the optimized conditions, the conversion of n-butanol is 89.7%, and the selectivity of butyl acetate is nearly 100%.

Water-soluble multicolored fluorescent CdTe quantum dots: Synthesis and application for fingerprint developing.

Multicolored water-soluble fluorescent CdTe quantum dots (QDs) have been synthesized by using Te, NaBH(4), and CdCl(2) as precursors and several mercapto-based compounds as modifiers. The effects of ratio of the precursor, type of modifier, refluxing time and initial pH value of the reaction on fluorescence intensity of CdTe QDs have been studied. XRD, HRTEM and fluorescence spectra were employed to characterize these samples. It is found that CdTe QDs with a crystalline size of 3-4nm are homogeneously embedded in the organic matrix. The maximum fluorescence emission peaks of CdTe QDs solutions shifted from 525nm to 591nm according to the refluxing time. The fingerprint details on the surface of smooth objects were clearly developed with CdTe QDs solution under irradiation of UV lights.

Solvothermal-induced phase transition and visible photocatalytic activity of nitrogen-doped titania.

Nitrogen-doped titania nanoparticles consisting of pure anatase, pure rutile and bicrystallites (anatase+rutile and anatase+brookite) have been prepared in TiCl(3)-HMT (hexamethylene tetramine)-alcohol solution under solvothermal process. The effect of the solvent type and amount of HMT as pH adjuster on the phase composition of titania and its visible photocatalytic activity for degradation to MO (methyl orange) was investigated. It is found that anatase gradually transferred to rutile with increase of carbon chain using methanol, ethanol, 1-propanol and 1-butanol as solvent. The pure anatase formed at the pH value of 1-2, while bicrystalline titania (anatase+rutile and anatase+brookite) at that of 7-10 in the presence of methanol. The bicrystalline (anatase+brookite) titania have the best visible photocatalytic activity among all the samples. The -(NO) and -(NH) dopants with an N (1s) binding energy of 400 eV may have positive effects on the visible light photocatalytic activity.