Enantiomerically Resolvable Inherent Chirality Induced by Strong Para-Steric Hindrance in Cycloparaphenylene-Based Carbon Nanohoops.

The chemical modification of the achiral carbon nanohoops to break the symmetry will result in inherently chiral structures with interesting optical properties. Herein, we report two novel π-extended chiral macrocycles, cyclo[10]paraphenylene-pyrene ([10]CPP-2Pyrene) and cyclo[10]paraphenylene-hexa-peri-hexabenzocoronene ([10]CPP-2HBC). The large substituents on the nanohoop peripheries effectively prevented free rotation and the racemization process. The conformation of each enantiomer is stable enough to be resolved by recycling HPLC.

Synthesis and Photophysical Properties of a Chiral Carbon Nanoring Containing Rubicene.

Herein we report the construction of an inherently chiral carbon nanoring, cyclo[7]paraphenylene-2,9-rubicene ([7]CPPRu2,9), by combining rubicene with a C-shaped synthon through the Suzuki-Miyaura coupling reaction. The structure was fully confirmed by high-resolution mass spectroscopies (HR-MS) and various NMR techniques. The photophysical properties were investigated by UV-vis absorption and fluorescence spectroscopy as well as the time-resolved fluorescence decay. Moreover, two enantiomers (M)/(P)-[7]CPPRu2,9 were successfully resolved by recyclable HPLC and studied by CD and CPL spectra.

Efficiency of Nanohydroxyapatite on Repairing Type II Diabetes Dental Implant-Bone Defect.

The purpose of this study was to see how a nanohydroxyapatite (n-HA) composite polyamide 66 (PA66) affected the repair of bone defects in diabetics with titanium implants, as well as to develop experimental materials for the creation of the interface between bone tissue and titanium implants. Rabbit bone marrow mesenchymal stem cells (MSCs) were isolated using n-HA/PA66 composite material, and the effect of coculture with the material on cell proliferation was analyzed after induction of mineralization. Bone defect models of diabetic experimental rabbits and titanium implants were prepared. Normal rabbits with bone defects were used as control (NC group, N = 8). After the diabetic bone defect (DM group, N = 8) and the implantation of n-HA/PA66 composite material (n-HA/PA66 group, N = 8), the differences in body weight, blood glucose, scanning electron microscopy of the implant-bone interface, bone mineral density, new bone trabecular parameters, histomorphology, and biomechanical properties of the implant-bone interface were compared and analyzed. In vitro test results showed that MSC cell growth could be promoted by mineralization induction, the cell growth condition was good after coculture with n-HA/PA66, and the proliferation activity of MSCs was not affected by the material. In vivo test results showed that the body weight of the DM group and n-HA/PA66 group was considerably inferior to that of the NC group, and the blood glucose was dramatically superior to that of the NC group (P < 0.05). However, the body weight of the n-HA/PA66 group was dramatically superior to that of the DM group (P < 0.05). The bone mineral density, bone volume fraction (BV/TV), bone surface area fraction (BS/BV), bone trabecular thickness (Tb.Th), bone trabecular number (Tb.N), bone trabecular area, and biomechanical properties in the DM group were considerably inferior to those in the NC group and n-HA/PA66 group (P < 0.05). The trabecular space (Tb.Sp) in the NC group and n-HA/PA66 group was dramatically superior to that in the NC group (P < 0.05). The bone mineral density, BV/TV, BS/BV, Tb.Th, Tb.N, trabecular area, and biomechanical properties of the n-HA/PA66 group were dramatically superior to those of the NC group (P < 0.05), while Tb.Sp was considerably inferior to that of the NC group (P < 0.05). These findings showed that the n-HA/PA66 material had good biocompatibility and minimal cytotoxicity, and that filling the space between the surrounding bone and the titanium implant can enhance bone repair. This research paved the way for future research into the tissue-engineered bone in the field of oral surgery.

Targeted delivery of edaravone by liposomes for the treatment of ischemic stroke.

Aim: To construct an edaravone-encapsulated liposomes (EDV-LIPs) formulation against acute ischemic stroke. Methods: EDV-LIPs were prepared by the film dispersion method. The biosafety was evaluated both in vitro and in vivo by flow cytometry and the histological staining method. Biodistribution and therapeutic effect of EDV-LIPs against acute ischemic stroke was investigated by fluorescent imaging, the behavior test, laser speckle imaging and triphenyltetrazolium chloride staining. Results: The nanoliposomes had a long circulation time and could accumulate in the brain lesion region in ischemic stroke rats. EDV-LIPs show good biosafety. EDV-LIPs could restore more cerebral blood flow, reduce infarct volume and decrease neuronal apoptosis. Conclusion: EDV-LIPs provide an effective alternative for drug-targeted delivery against acute ischemic stroke.

Nanometer precise red blood cell sizing using a cost-effective quantitative dark field imaging system.

Because of the bulk, complexity, calibration requirements, and need for operator training, most current flow-based blood counting devices are not appropriate for field use. Standard imaging methods could be much more compact, inexpensive, and with minimal calibration requirements. However, due to the diffraction limit, imaging lacks the nanometer precision required to measure red blood cell volumes. To address this challenge, we utilize Mie scattering, which can measure nanometer-scale morphological information from cells, in a dark-field imaging geometry. The approach consists of a custom-built dark-field scattering microscope with symmetrically oblique illumination at a precisely defined angle to record wide-field images of diluted and sphered blood samples. Scattering intensities of each cell under three wavelengths are obtained by segmenting images via digital image processing. These scattering intensities are then used to determine size and hemoglobin information via Mie theory and machine learning. Validation on 90 clinical blood samples confirmed the ability to obtain mean corpuscular volume (MCV), mean corpuscular hemoglobin concentration (MCHC), and red cell distribution width (RDW) with high accuracy. Simulations based on historical data suggest that an instrument with the accuracy achieved in this study could be used for widespread anemia screening.

Folic acid modified Fe3O4 nanoclusters by a one-step ultrasonic technique for drug delivery and MR imaging.

Multifunctional nanoclusters based on Fe3O4 nanoparticles for magnetic resonance imaging (MRI) and drug delivery are reported here. At first, oleic acid (OA)-coated Fe3O4 nanoparticles were prepared. Then block copolymer Pluronic F127 or folic acid (FA) conjugated-Pluronic F127 was used to modify the hydrophobic nanoparticles to become hydrophilic Fe3O4@F127 nanoclusters via facile ultrasonic treatment. During this process, drug molecules can also be introduced into the nanoclusters and therefore the targeted drug delivery system was formed. Next, we verified the feasibility of the nanoclusters as drug delivery vehicles and magnetic contrast agents. The nanoclusters have an average size of 200 nm and remained stable in water for long periods. Folic acid-modified nanoclusters showed an enhanced intracellular uptake into HepG2 cells by using both cellular iron amount analysis and flow cytometry analysis. Besides, Fe3O4@F127@FA nanoclusters showed good compatibility in the tested concentration range and good sensitivity in T 2-weighted MRI. The magnetic nanoclusters combined with drug delivery properties have greatly increased the significance in the diagnosis and therapy of diseases, which are suitable for systematical administration of hydrophobic drugs and simultaneously MRI diagnosis.

Selective Synthesis of Conjugated Chiral Macrocycles: Sidewall Segments of (-)/(+)-(12,4) Carbon Nanotubes with Strong Circularly Polarized Luminescence.

Carbon nanotubes (CNTs) have unusual physical properties that are valuable for nanotechnology and electronics, but the chemical synthesis of chirality- and diameter-specific CNTs and π-conjugated CNT segments is still a great challenge. Reported here are the selective syntheses, isolations, characterizations, and photophysical properties of two novel chiral conjugated macrocycles ([4]cyclo-2,6-anthracene; [4]CAn2,6 ), as (-)/(+)-(12,4) carbon nanotube segments. These conjugated macrocyclic molecules were obtained using a bottom-up assembly approach and subsequent reductive elimination reaction. The hoop-shaped molecules can be directly viewed by a STM technique. In addition, chiral enantiomers with (-)/(+) helicity of the [4]CAn2,6 were successfully isolated by HPLC. The new tubular CNT segments exhibit large absorption and photoluminescence redshifts compared to the monomer unit. The carbon enantiomers are also observed to show strong circularly polarized luminescence (glum ≈0.1). The results reported here expand the scope of materials design for bottom-up synthesis of chiral macrocycles and enrich existing knowledge of their optoelectronic properties.

The Supramolecular Chemistry of Cycloparaphenylenes and Their Analogs.

Cycloparaphenylenes (CPPs) and their analogs have recently attracted much attention due to their aesthetical structures and optoelectronic properties with radial π-conjugation systems. The past 10 years have witnessed a remarkable advancement in CPPs research, from synthetic methodology to optoelectronic investigations. In this present minireview, we highlight the supramolecular chemistry of CPPs and their analogs, mainly focusing on the size-selective encapsulation of fullerenes, endohedral metallofullerenes, and small molecules by these hoop-shaped macrocycles. We will also discuss the assembly of molecular bearings using some belt-persistent tubular cycloarylene molecules and fullerenes, photoinduced electron transfer properties in supramolecular systems containing carbon nanohoop hosts and fullerene guests, as well as the shape recognition properties for structure self-sorting by using dumbbell-shaped dimer of [60]fullerene ligand. Besides, the supramolecular complexes with guest molecules other than fullerenes, such as CPPs themselves, iodine, pyridinium cations, and bowl-shaped corannulene, are also discussed.

MiR-223-3p functions as a tumor suppressor in lung squamous cell carcinoma by miR-223-3p-mutant p53 regulatory feedback loop.

BACKGROUND: MicroRNAs have an important role in diverse biological processes including tumorigenesis. MiR-223 has been reported to be deregulated in several human cancer types. However, its biological role has not been functionally characterized in lung squamous cell carcinoma (LSCC). The following study investigates the role of miR-223-3p in LSCC growth and metastasis and its underlying mechanism. METHODS: MicroRNA profiling analyses were conducted to determine differential miRNAs expression levels in LSCC tumor tissues that successfully formed xenografts in immunocompromised mice (XG) and failed tumor tissues (no-XG). RT-PCR and in situ hybridization (ISH) was performed to evaluate the expression of miR-223-3p in 12 paired adjacent normal tissues and LSCC specimens. Cell proliferation and migration were assessed by CCK-8, colony formation and Transwell assay, respectively. The role of miR-223-3p in LSCC tumorigenesis was examined using xenograft nude models. Bioinformatics analysis, Dual-luciferase reporter assays, Chromatin immunoprecipitation (ChIP) assay and Western blot analysis were used to identify the direct target of miR-223-3p and its interactions. RESULTS: MiR-223-3p was downregulated in LSCC tissues that successfully formed xenografts (XG) compared with tumor tissues that failed (no-XG), which was also significantly reduced in LSCC tissues compared with the adjacent normal tissues. Gain- and loss-of function experiments showed that miR-223-3p inhibited proliferation and migration in vitro. More importantly, miR-223-3p overexpression greatly suppressed tumor growth in vivo. Mechanistically, we found that mutant p53 bound to the promoter region of miR-223 and reduced its transcription. Meanwhile, p53 is a direct target of miR-223-3p. Thus, miR-223-3p regulated mutant p53 expression in a feedback loop that inhibited cell proliferation and migration. CONCLUSIONS: Our study identified miR-223-3p, as a tumor suppressor gene, markedly inhibited cell proliferation and migration via miR-223-3p-mutant p53 feedback loop, which suggested miR-223-3p might be a new therapeutic target in LSCC bearing p53 mutations.

Impact of the preoperative prognostic nutritional index on postoperative and survival outcomes in colorectal cancer patients who underwent primary tumor resection: a systematic review and meta-analysis.

PURPOSE: We aimed to explore whether the preoperative prognostic nutritional index (PNI) could be an indicator of prognostic outcomes in colorectal cancer (CRC) patients. METHODS: A systematic review and meta-analysis was conducted using the PubMed, Embase, and Web of Science databases. All original comparative studies published in English that were related to a high PNI versus a low PNI in CRC patients were included. RESULTS: A total of 10 studies involving 6372 patients were included in our meta-analysis. Our overall analysis indicated that the low-PNI group had a significantly reduced overall survival (OS) (HR = 1.87, 95% CI = 1.45-2.42, P < 0.01), cancer-specific survival (HR = 1.53, 95% CI = 1.07-2.19, P = 0.02), and disease-free survival (HR = 1.67, 95% CI = 1.23-2.26, P < 0.01) compared with the high-PNI group. Furthermore, our subgroup results indicated that a high PNI could be a significant indicator of improved OS in TNM stage II (HR = 1.93, 95% CI = 1.29-2.90, P < 0.01) and III (HR = 1.71, 95% CI = 1.25-2.34, P < 0.01), and a similar trend in TNM stage I or IV could also be observed though without statistical significance. Regarding postoperative complications, our pooled results indicated that the low-PNI group had a significantly increased incidence of total and severe postoperative complications. CONCLUSIONS: Our findings indicated that CRC patients with a preoperative high PNI had a significantly improved OS. However, almost only Asian CRC patients were included based on current issue.

Identification of differentially expressed genes and biological characteristics of colorectal cancer by integrated bioinformatics analysis.

Colorectal cancer (CRC) ranks as one of the most common malignant tumors worldwide. Its mortality rate has remained high in recent years. Therefore, the aim of this study was to identify significant differentially expressed genes (DEGs) involved in its pathogenesis, which may be used as novel biomarkers or potential therapeutic targets for CRC. The gene expression profiles of GSE21510, GSE32323, GSE89076, and GSE113513 were downloaded from the Gene Expression Omnibus (GEO) database. After screening DEGs in each GEO data set, we further used the robust rank aggregation method to identify 494 significant DEGs including 212 upregulated and 282 downregulated genes. Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analyses were performed by DAVID and the KOBAS online database, respectively. These DEGs were shown to be significantly enriched in different cancer-related functions and pathways. Then, the STRING database was used to construct the protein-protein interaction network. The module analysis was performed by the MCODE plug-in of Cytoscape based on the whole network. We finally filtered out seven hub genes by the cytoHubba plug-in, including PPBP, CCL28, CXCL12, INSL5, CXCL3, CXCL10, and CXCL11. The expression validation and survival analysis of these hub genes were analyzed based on The Cancer Genome Atlas database. In conclusion, the robust DEGs associated with the carcinogenesis of CRC were screened through the GEO database, and integrated bioinformatics analysis was conducted. Our study provides reliable molecular biomarkers for screening and diagnosis, prognosis as well as novel therapeutic targets for CRC.

Identification of a five-gene signature with prognostic value in colorectal cancer.

Colorectal cancer (CRC) ranks as one of the most commonly diagnosed malignancies worldwide. Although mortality rates have been decreasing, the prognosis of CRC patients is still highly dependent on the individual. Therefore, identifying and understanding novel biomarkers for CRC prognosis remains crucial. The gene expression profiles of five-gene expression omnibus (GEO) data sets of CRC were first downloaded. A total of 352 consistent differentially expressed genes (DEGs) were identified for CRC and paired with normal tissues. Functional analysis including gene ontology and Kyoto encyclopedia of genes and genomes pathway enrichment revealed that these DEGs were related to metabolic pathways, tight junctions, and the cell cycle. Ten hub DEGs were identified based on the search tool for the retrieval of interacting genes database and protein-protein interaction networks. By using univariate Cox proportional hazard regression analysis, we found 11 survival-related genes among these DEGs. We finally established a five-gene signature (kinesin family member 15, N-acetyltransferase 2, glutathione peroxidase 3, secretogranin II, and chloride channel accessory 1) with prognostic value in CRC by step multivariate Cox regression analysis. Based on this risk scoring system, patients in the high-risk group had significantly poorer survival results compared with those in the low-risk group (log-rank test, p < 0.0001). Finally, we validated our gene signature scoring system in two independent GEO cohorts (GSE17536 and GSE33113). We found all five of the signature genes to be DEGs in The Cancer Genome Atlas database. In conclusion, our findings suggest that our five DEG-based signature can provide a novel biomarker with useful applications in CRC prognosis.

Can sarcopenia be a predictor of prognosis for patients with non-metastatic colorectal cancer? A systematic review and meta-analysis.

PURPOSE: We aimed to explore whether sarcopenia diagnosed with the third lumbar vertebra skeletal muscle index (L3 SMI) can be a predictor of prognosis for colorectal cancer (CRC) patients. METHODS: A systematic review and meta-analysis was conducted using PubMed, Embase, and the Web of Science databases. All original comparative studies published in English that were related to sarcopenia versus non-sarcopenia in non-metastatic CRC patients based on postoperative and survival outcomes were included. Data synthesis and statistical analysis were carried out using Stata software. RESULTS: A total of 12 studies including 5337 patients were included in our meta-analysis. In our overall analyses of postoperative outcomes, we indicated that CRC patients with sarcopenia would have longer hospital stays, higher incidence of total postoperative morbidity (OR = 1.70, 95% CI = 1.07-2.70, P < 0.01), mortality (OR = 3.45, 95% CI = 1.69-7.02, P < 0.01), and infection (OR = 2.21, 95% CI = 1.50-3.25, P < 0.01) but not anastomosis leakage or intestinal obstruction when compared to non-sarcopenia patients. Regarding survival outcomes, our results showed that sarcopenia predicted a decreased overall survival (HR = 1.63, 95% CI = 1.24-2.14, P < 0.01), disease-free survival, and cancer-specific survival for non-metastatic CRC patients. Moreover, our subgroup analyses showed similar tendency with our overall analyzed results. CONCLUSIONS: Sarcopenia diagnosed with L3 SMI can be a negative predictor of postoperative and survival outcomes for non-metastatic CRC patients. Prospective studies with a uniform definition of sarcopenia are needed to update our findings.

Patient-derived tumor xenografts of lung squamous cell carcinoma alter long non-coding RNA profile but not responsiveness to cisplatin.

Lung squamous cell carcinoma (LSCC), the second most common type of lung cancer, has received limited attention. Patient-derived tumor xenografts (PDTXs) are useful preclinical models to reproduce the diverse heterogeneity of cancer, but it is important to identify potential variations during their establishment. A total of 18 PDTXs were established from 37 the surgical specimens and 16 were serially passaged to third generation. Second- and third-generation xenografts had a faster growth rate in mice. The tumor implantation success rate was associated with poorer differentiation, larger tumor volume and higher expression of Ki-67. The xenografts largely retained histological and key immunophenotypic features (including p53, p63, cytokeratin5/6, and E-cadherin). However, increased Ki-67 expression was identified in partial xenografts. Long non-coding RNA (lncRNA) and mRNA expression in third-generation xenografts differed from that of matched primary tumors. Gene Ontology and pathway analysis showed that mRNAs involved in cell cycle, and metabolism regulation were generally upregulated in xenografts, while those associated with immune responses were typically downregulated. Furthermore, the responses of xenografts to cisplatin were consistent with clinical outcome. In the present study, PDTXs of SCC were successfully established, and closely resembled their original tumor regarding their immunophenotype and response to cisplatin. Overall, PDTXS of LSCC altered the lncRNA profile and increased the proliferative activity of cancer cells, whilst retaining responsiveness to cisplatin.

A Three-Dimensional Capsule-like Carbon Nanocage as a Segment Model of Capped Zigzag [12,0] Carbon Nanotubes: Synthesis, Characterization, and Complexation with C70.

Herein we report the synthesis and photophysical and supramolecular properties of a novel three-dimensional capsule-like hexa-peri-hexabenzocoronene (HBC)-containing carbon nanocage, tripodal-[2]HBC, which is the first synthetic model of capped zigzag [12,0] carbon nanotubes (CNTs). Tripodal-[2]HBC was synthesized by the palladium-catalyzed coupling of triboryl hexabenzocoronene and L-shaped cyclohexane units, followed by nickel-mediated C-Br/C-Br coupling and subsequent aromatization of the cyclohexane moieties. The physical properties of tripodal-[2]HBC and its supramolecular host-guest interaction with C70 were further studied by UV/Vis and fluorescence spectroscopy. Theoretical calculations revealed that the strain energy of tripodal-[2]HBC was as high as 55.2 kcal mol-1 .

Facile fabrication of water-dispersible nanocomposites based on hexa-peri-hexabenzocoronene and Fe3O4 for dual mode imaging (fluorescent/MR) and drug delivery.

The facile fabrication of multifunctional nanocomposites (Fe3O4/HBC@F127) consisting of superparamagnetic Fe3O4 nanoparticles and fluorescent organic hexa-peri-hexabenzocoronene (HBC) molecules incorporated in block copolymer diacylphospholipid-polyethyleneglycol F127 have been demonstrated for dual mode imaging (fluorescent/MR) and drug delivery. The obtained nanocomposites were water-dispersible, stable and biocompatible, as confirmed by dynamic light scattering (DLS) and 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. Relativity measurements showed a T 2 relaxivity (r 2) of 214.61 mM-1 s-1, which may be used as T 2-weighted MR imaging agents. In vitro imaging studies indicated that the nanocomposites had good MR and fluorescence imaging effects with low cytotoxicity. Besides, the developed nanocomposites could also be applied as drug delivery vehicles. Doxorubicin (DOX) loaded Fe3O4/HBC@F127 nanocomposites significantly inhibited the growth of human hepatoma cells (HepG2). These findings suggested that the facile synthesized multifunctional nanocomposites may be used as a platform for dual mode imaging (both MR and fluorescence) and drug delivery.

lncRNA PVT1 in cancer: A review and meta-analysis.

OBJECTIVES: Plasmacytoma variant translocation 1 (PVT1) is a newly discovered long non-coding RNA that functions as an oncogenic molecule in different cancers. We conducted a systematic review and meta-analysis to determine its prognostic potential for malignant tumors. MATERIALS AND METHODS: A literature survey was conducted by searching the PubMed, Web of Science, Cochrane Library, China National Knowledge Infrastructure and Wanfang electronic databases for articles published as of June 1, 2017. Hazard ratios (HRs) and 95% confidence intervals (95% CIs) were calculated to demonstrate the relationship between PVT1 expression and overall survival (OS) and disease-free survival (DFS) using RevMan 5.2 and Stata 12.0 software. A quality assessment of the included studies was performed according to the Newcastle-Ottawa scale. RESULTS: A total of 1443 patients from 15 studies were included in this meta-analysis. Elevated PVT1 expression was significantly correlated with poor overall survival (HR=2.03, 95% CI: 1.69-2.43) and disease-free survival (HR=1.55, 95% CI: 1.29-1.87). Statistical significance was also observed in a subgroup meta-analysis that was stratified by variance analysis, cancer type, sample size and PVT1 cut-off value. Additionally, increased PVT1 expression was significantly associated with positive lymph node metastasis (odds ratio (OR)=1.94, 95% CI: 1.03-3.68), positive distant metastasis (OR=3.85, 95% CI: 2.14-6.93), advanced tumor-node-metastasis stage (OR=3.19, 95% CI: 2.45-4.15) and poor differentiation grade (OR=1.57, 95% CI: 1.15-2.16), but not tumor size (P>0.05). CONCLUSION: Elevated PVT1 expression was related to poor prognosis and might be a potential biomarkerof clinicopathological characteristics in different cancer types. More studies need to be conducted to verify the clinical value of PVT1 in human cancers.

A Large π-Extended Carbon Nanoring Based on Nanographene Units: Bottom-Up Synthesis, Photophysical Properties, and Selective Complexation with Fullerene C70.

Herein we report the organoplatinum-mediated bottom-up synthesis, characterization, and properties of a novel large π-extended carbon nanoring based on a nanographene hexa-peri-hexabenzocoronene (HBC) building unit. This tubular structure can be considered as an example of the longitudinal extension of the cycloparaphenylene scaffold to form a large π-extended carbon nanotube (CNT) segment. The cyclic tetramer of a tetramesityl HBC ([4]CHBC) was synthesized by the reaction of a 2,11-diborylated hexa-peri-hexabenzocoronene with a platinum complex, followed by reductive elimination. The structure of this tubular molecule was further confirmed by physical characterization. Theoretical calculations indicate that the strain energy of this nanoring is as high as 49.18 kcal mol-1 . The selective supramolecular host-guest interaction between [4]CHBC and C70 was also investigated.

Pyrolyzed cobalt porphyrin-based conjugated mesoporous polymers as bifunctional catalysts for hydrogen production and oxygen evolution in water.

In this present study, a series of cobalt porphyrin-based conjugated mesoporous polymers (CoP-nph-CMP, n = 2, 3, 4) were fabricated as catalyst precursors to generate bifunctional catalysts via pyrolysis (CoP-nph-CMP-800, n = 2, 3, 4) for both the oxygen evolution reaction (OER) and the hydrogen evolution reaction (HER). Among these catalysts, CoP-2ph-CMP-800 exhibited the best catalytic activity with quite a low overpotential for both the OER (η = 370 mV for 10 mA cm-2) and the HER (η = 360 mV for 10 mA cm-2). Moreover, their excellent bifunctional catalytic performance was also explored in the overall water splitting test (η = 760 mV for 10 mA cm-2).

Synergistic Effect of a Molecular Cocatalyst and a Heterojunction in a 1 D Semiconductor Photocatalyst for Robust and Highly Efficient Solar Hydrogen Production.

Photocatalytic production of hydrogen by water splitting is a promising pathway for the conversion of solar energy into chemical energy. However, the photocatalytic conversion efficiency is often limited by the sluggish transfer of the photogenerated charge carriers, charge recombination, and subsequent slow catalytic reactions. Herein, we report a highly active noble-metal-free photocatalytic system for hydrogen production in water. The system contains a water-soluble nickel complex as a molecular cocatalyst and zinc sulfide on 1D cadmium sulfide as the heterojunction photocatalyst. The complex can efficiently transport photogenerated electrons and holes over a heterojunction photocatalyst to hamper charge recombination, leading to highly improved catalytic efficiency and durability of a heterojunction photocatalyst- molecular cocatalyst system. The results show that under optimal conditions, the average apparent quantum yield was approximately 58.3 % after 7 h of irradiation with monochromatic 420 nm light. In contrast, the value is only 16.8 % if the molecular cocatalyst is absent. Such a remarkable performance in a molecular cocatalyst-based photocatalytic system without any noble metal loading has, to the best of our knowledge, not been reported to date.