Ultrafine Iridium Nanoparticles Anchored on Co-Based Metal-Organic Framework Nanosheets for Robust Hydrogen Evolution in Alkaline Media.

A highly promising electrocatalyst has been designed and prepared for the hydrogen evolution reaction (HER). This involves incorporating well-dispersed Ir nanoparticles into a cobalt-based metal-organic framework known as Co-BPDC [Co(bpdc)(H2O)2, BPDC: 4,4'-biphenyldicarboxylic acid]. Ir@Co-BPDC demonstrates exceptional HER activity in alkaline media, surpassing both commercial Pt/C and recent noble-metal catalysts. Theoretical results indicate that electron redistribution, induced by interfacial bonds, optimizes the adsorption energy of water and hydrogen, thereby enhancing our understanding of the superior properties of Ir@Co-BPDC for HER.

Plasmonic Ni3N Cocatalyst Boosting Directional Charge Transfer and Separation toward Synergistic Photocatalytic-Photothermal Performance of Hydrogen and Benzaldehyde Production as Well as Bacterial Inactivation.

Charge separation and transfer are the dominating factors in achieving high activity of solar energy-based photocatalysis. Here, a plasmonic transition metal nitride, Ni3N, nanosheet was fabricated and employed as an efficient cocatalyst to couple with Cd0.9Zn0.1S (CZS) solid solution via a self-assembly method to form a novel Ni3N/CZS heterojunction with an intimate interface. On one hand, localized surface plasmon resonance of the Ni3N nanosheets endowed the fabricated Ni3N/CZS composite with a wide-spectrum light absorption capacity, even to the near-infrared range. On the other hand, Ni3N as a cocatalyst can not only effectively induce the directional electron transfer from CZS to Ni3N active sites but also enhance the surface charge separation efficiency of the Ni3N/CZS heterojunction by 4.1 times compared to that of pure CZS. Plasmonic Ni3N also provided a photothermal effect to enhance the surface temperature of the composite for boosting the catalytic reaction kinetics. As a result, under visible light irradiation, the optimal Ni3N/CZS composite exhibited simultaneous H2 generation and benzaldehyde formation rates of 35.08 and 16.44 mmol g-1 h-1, which were 9.4 and 5.9 times those of CZS, respectively; and the composite also demonstrated a strong antibacterial ability with a sterilization rate of 99.7% toward Escherichia coli. Besides that, under NIR light, plasmonic Ni3N offered extra hot electrons that can transfer back to CZS to take part in the photocatalytic reaction, leading to the Ni3N/CZS composite still having a high H2 production of 179.6 µmol g-1 h-1. This work focuses on developing and applying novel plasmonic cocatalysts in photocatalysis for achieving adjustable electron transfer and fast charge separation for extensive practical application.

Boosting Interfacial Charge Transfer with a Giant Internal Electric Field in a TiO2 Hollow-Sphere-Based S-Scheme Heterojunction for Efficient CO2 Photoreduction.

The construction of an S-scheme charge transfer pathway is considered to be a powerful way to inhibit charge recombination and maintain photogenerated carriers with high redox capacity to meet the kinetic requirements of the carbon dioxide (CO2) photoreduction reaction. For an S-scheme heterojunction, an internal electric field (IEF) is regarded as the main driving force for accelerating the interfacial spatial transfer of photogenerated charges. Herein, we designed a TiO2 hollow-sphere (TH)-based S-scheme heterojunction for efficient CO2 photoreduction, in which WO3 nanoparticles (WP) were applied as an oxidation semiconductor to form an intimate interfacial contact with the TH. The S-scheme charge transfer mode driven by a strong IEF for the TH/WP composite was confirmed by in situ X-ray photoelectron spectroscopy and ultraviolet photoelectron spectroscopy. As a result, abundant photogenerated electrons with strong reducing ability would take part in the CO2 reduction reaction. The combination of surface photovoltage spectra and transient photocurrent experiments disclosed that the IEF intensity and charge separation efficiency of the fabricated TH/WP composite were nearly 16.80- and 1.42-fold higher, respectively, than those of the pure TH. Furthermore, sufficient active sites provided by the hollow-sphere structure also enhanced the kinetics of the catalytic reaction. Consequently, the optimized TH/WP composite showed a peak level of CO production of 14.20 µmol g-1 in 3 h without the addition of any sacrificial agent. This work provides insights into the kinetic studies of the S-scheme charge transfer pathway for realizing high-performance CO2 photoreduction.

Construction of a ZnIn2S4/Au/CdS Tandem Heterojunction for Highly Efficient CO2 Photoreduction.

Photocatalytic CO2 reduction technology is of great importance to alleviate energy crisis and environmental pollution; however, it remains a serious challenge due to the fast recombination of carriers. In this study, we report a three-dimensional structure of a ZnIn2S4/Au/CdS composite photocatalyst for the CO2 reduction reaction, where Au nanoparticles (NPs) are evenly anchored on the surface of ZnIn2S4 by photodeposition and Au NPs are wrapped around by CdS. In ZnIn2S4/Au/CdS composite photocatalysts, Au NPs act as a bridge to construct a "semiconductor-metal-semiconductor" tandem electron transfer mechanism (ZnIn2S4 → Au → CdS) heterojunction, which greatly promotes the transfer of photogenerated electrons. It is worth noting that Au NPs, as a local surface plasmon resonance (LSPR) effect excited source to generate excited-state electrons, further improve the photoreduction CO2 activity. Under UV-vis light irradiation, the CO yield of ZnIn2S4/Au/CdS can reach 63.07 µmol·g-1·h-1, which is higher than that of 6.37 µmol·g-1·h-1 for pure ZnIn2S4, 0.93 µmol·g-1·h-1 for CdS, 8.9 µmol·g-1·h-1 for ZnIn2S4/CdS, 31.04 µmol·g-1·h-1 for ZnIn2S4/Au, and 5.37 µmol·g-1·h-1 for CdS/Au. In addition, the ternary ZnIn2S4/Au/CdS composite photocatalyst has good cyclic stability. This study broadens the idea of designing photocatalysts with good carrier separation efficiency.

Constructed Z-Scheme g-C3N4/Ag3VO4/rGO Photocatalysts with Multi-interfacial Electron-Transfer Paths for High Photoreduction of CO2.

Z-scheme g-C3N4/Ag3VO4/reduced graphene oxide (rGO) photocatalysts with multi-interfacial electron-transfer paths enhancing CO2 photoreduction under UV-vis light irradiation were successfully prepared by a hydrothermal process. Transmission electron microscope images displayed that the prepared photocatalysts have a unique 2D-0D-2D ternary sandwich structure. Photoelectrochemical characterizations including TPR, electrochemical impedance spectroscopy, photoluminescence, and linear sweep voltammetry explained that the multi-interfacial structure effectively improved the separation and transmission capabilities of photogenerated carriers. Electron spin resonance spectroscopy and band position analysis proved that the electron-transfer mode of g-C3N4/Ag3VO4 meets the Z-scheme mechanism. The introduction of rGO provided more electron-transfer paths for the photocatalysts and enhanced the stability of Ag-based semiconductors. In addition, the π-π conjugation effect between g-C3N4 and rGO further improved the generation and separation efficiency of photogenerated electron-hole pairs. Then, the multiple channels (Ag3VO4 → CN, Ag3VO4 → rGO → CN, and rGO → CN) due to the 2D-0D-2D structure greatly improving the photocatalytic CO2 reduction ability have been discussed in detail.

Preparation and research of PCL/cellulose composites: Cellulose derived from agricultural wastes.

For the rational use of agricultural wastes, bagasse, orange peel and wheat bran were used to fabricate bio-based polymer materials. Cellulose was extracted from the three different agricultural wastes, and poly(ε-caprolactone) (PCL) was used as the matrix material. PCL was mixed with nanocrystalline cellulose (CNC), extracted bagasse cellulose (GC), orange peel cellulose (JC) and wheat bran cellulose (MC) by solution casting. Morphology and structure of the extracted cellulose were studied by Scanning Electron Microscope, Fourier Infrared spectrometer, thermogravimetry and X-ray diffractometer. The influence of GC, JC, MC on the crystallization process and mechanical properties of PCL was investigated by DSC and tensile test. Experimental results show that the addition of CNC, GC, JC, MC increases the crystallization temperature of PCL, accelerates the crystallization process of PCL, and improves the tensile property of PCL.

Boosting photocatalytic synchronous production of H2 coupled with acetone over Co doped Cu3P quantum dots/ZnIn2S4 nanosheets p-n nanojunction.

Photocatalysis provides a new way for synchronous H2 production and organic synthesis at normal temperature and pressure, usually, water and organic substrate function as sources of hydrogen protons and organic products, which are complex and limited by two half-reactions. Employing alcohols as reaction substrates to simultaneously produce H2 and valuable organics in a redox cycle is worthy studying, to which catalyst design at atomic level holds the key. In this paper, Co elements doped Cu3P (CoCuP) quantum dots (QDs) are prepared and coupled with ZnIn2S4 (ZIS) nanosheets to form a 0D/2D p-n nanojunction which can effectively boost aliphatic and aromatic alcohols activation to simultaneously produce H2 and corresponding ketones (or aldehydes). The optimal CoCuP/ZIS composite demonstrated the highest activity for dehydrogenation of isopropanol to acetone (17.77 mmol⋅g-1⋅h-1) and H2 (26.8 mmol⋅g-1⋅h-1), which was 2.40 and 1.63 times higher than that of Cu3P/ZIS composite, respectively. Mechanistic investigations revealed that such high-performance originated from the accelerated electron transfer of the formed p-n junction and the thermodynamic optimization caused by the Co dopant which was the active site of oxydehydrogenation as a prerequisite step for isopropanol oxidation over the surface of the CoCuP/ZIS composite. Besides that, coupling of the CoCuP QDs can lower the dehydrogenation activation energy of isopropanol to form a key radical intermediate of (CH3)2CHO* for improving the activity of simultaneous production of H2 and acetone. This strategy provides an overall reaction strategy to obtain two meaningful products (H2 and ketones (or aldehydes)) and deeply explores the integrated redox reaction of alcohol as substrate for high solar-chemical energy conversion.

Bufalin reverses ABCB1-mediated resistance to docetaxel in breast cancer.

Background: Docetaxel (DCT) is widely used in clinical practice, but the drug resistance of breast cancer patients has become an important reason to limit its clinical efficacy. Chan'su is a commonly used traditional Chinese medicine for the treatment of breast cancer. Bufalin (BUF) is a bioactive polyhydroxy steroid extracted from chan'su and has strong antitumor activity, but there are few studies on reversing drug resistance in breast cancer. The aim of this study is to determine whether BUF can reverse the drug resistance to DCT and restore efficacy in breast cancer. Methodology: The reversal index of BUF was detected by Cell Counting Kit-8 (CCK-8) assays. The effects of BUF on enhancing the apoptosis of DCT were detected by flow cytometry and Western Blot (WB), and the main differential expression levels of sensitive and resistant strains were detected by high-throughput sequencing. Rhodamine 123 assay, WB and ATP Binding Cassette Subfamily B Member 1 (ABCB1) ATPase activity experiments were used to detect the effect of BUF on ABCB1. The nude mouse orthotopic model was constructed to investigate the reversal effect of BUF on DCT resistance in vivo. Results: With BUF intervention, the sensitivity of drug-resistant cell lines to DCT was increased. BUF can inhibit the expression of ABCB1 protein, increase the drug accumulation of DCT in drug-resistant strains, and reduce the ATPase activity of ABCB1. Animal experiments show that BUF can inhibit the growth of drug-resistant tumors in an orthotopic model of breast cancer and decrease the expression of ABCB1. Conclusion: BUF can reverse ABCB1-mediated docetaxel resistance in breast cancer.

Incorporating Ni-Polyoxometalate into the S-Scheme Heterojunction to Accelerate Charge Separation and Resist Photocorrosion for Promoting Photocatalytic Activity and Stability.

The emerging polyoxometalate (POM) nanomaterials are transition metal oxygen anion clusters with d0 electronic configurations, which could be attractive and potential photocatalysts. Hence, a nickel (Ni)-substituted polyoxometalate K6Na4[Ni4(H2O)2(PW9O34)2]·32H2O (Ni4POM)-incorporating step (S)-scheme heterojunction was developed to promote photocatalytic activity and stability in H2 and H2O2 production. The multielectron transfer through variable valence metal centers in Ni4POM would facilitate the recombination of invalid charges through the S-scheme pathway. Moreover, incorporating Ni4POM into the S-scheme heterojunction can broaden the light absorption range and meanwhile lead to resistance to photocorrosion to promote the optical and chemical stability of Cd0.5Zn0.5S (CZS). The optimized CZSNi-70 exhibited a H2 evolution rate of 42.32 mmol g-1 h-1 under visible-light irradiation with an apparent quantum yield of 32.27% at 420 nm and a H2O2 production rate of 295.4 µmol L-1 h-1 under 420 nm light-emitting diode irradiation. This work can provide a new view for the development of transition metal-substituted POM-based stable and efficient S-scheme photocatalysts.

Constructing Schottky junctions via Pd nanosheets on DUT-67 surfaces to accelerate charge transfer.

The separation, transfer and recombination of charge often affect the rate of photocatalytic reduction of CO2. Schottky junctions can promote the rapid separation of space charge. Therefore, in this paper, Pd nanosheets were grown on the surface of DUT-67 by a hydrothermal method, and a Schottky junction was constructed between DUT-67 and Pd. Under the action of the Schottky junction, the CO yield of 0.3-Pd/DUT-67 reached 12.15 µmol/g/h, which was 17 times higher than that of DUT-67. Efficient charge transfer was demonstrated in photochemical experiments. The large specific surface area and the increased light utilization rate also contributed to the increase in the CO2 reduction efficiency. In addition, the mechanism of Pd/DUT-67 photocatalytic reduction of CO2 was proposed.

Multichannel Electron Transmission and Fluorescence Resonance Energy Transfer in In2S3/Au/rGO Composite for CO2 Photoreduction.

Efficient electron transmission is an important step in the process of CO2 photoreduction. In this paper, a multi-interface-contacted In2S3/Au/reduced graphene oxide (rGO) photocatalyst with the fluorescence resonance energy transfer (FRET) mechanism has been successfully prepared by the solvothermal, self-assembly, and hydrothermal reduction processes. Photocatalytic CO2 reduction experiments showed that the In2S3/Au/rGO (IAr-3) composite exhibited excellent photoreduction performance and photocatalytic stability. The yields of CO and CH4 obtained after the photoreduction process with IAr-3 as the catalyst were around 4 and 6 times higher than those of pure In2S3, respectively. Photoelectrochemical analysis showed that the multi-interface contact and FRET mechanism greatly improved the generation, transmission, and separation efficiency of carriers photogenerated within the photocatalyst. In situ FTIR test was applied to analyze the photocatalytic CO2 reduction process. 13C isotope tracer test confirmed that the carbon source of CO and CH4 was the CO2 molecules in the photoreduction process rather than the decomposition of catalyst or TEOA. A potential enhanced photocatalytic mechanism has been discussed in total.