Latest ArticlesPhotocatalytic hydrogen peroxide (H2O2) production has been considered as a promising strategy for H2O2 synthesis due to its environmentally friendly. Among various photocatalysts, carbon nitride-based materials are excellent candidates for H2O2 production because of their excellent visible-light response, low cost and high stability. In this review, we summarize in detail the research progress on the photocatalytic production of H2O2 by carbon nitride. First, we summarize the basic principles of photocatalysis and photocatalytic H2O2 production. Second, the classification and modification methods of carbon-nitride-based materials are discussed, including morphology modulation, noble metal loading, defect control, heterojunction regulation, molecular structure engineering and elemental doping. Finally, the different in-situ applications of H2O2 via photosynthesis were discussed, including disinfection and antibiotic resistant genes degradation, organic pollutants degradation, medical applications and fine chemical synthesis. This review brings great promise for in-situ H2O2 photosynthesis, which is expected to serve as a key component in future applications.
Flexible energy storage devices have been paid much attention and adapts to apply in various fields. Benefiting from the active sites of boron (B) and phosphorus (P) doping materials, co-doped carbon materials are widely used in energy storage devices for the enhanced electrochemical performance. Herein, B and P co-doped flexible carbon nanofibers with nitrogen-rich (B-P/NC) are investigated with electrospinning for sodium-ion battery. The flexible of binderless B-P/NC with annealing of 600 ℃ (B-P/NC-600) exhibits the remarkable performance for the robust capacity of 200 mAh/g at 0.1 A/g after 500 cycles and a durable reversible capacity of 160 mAh/g even at 1 A/g after 12, 000 cycles, exhibiting the equally commendable stability of flexible B-P/NC-600. In addition, B-P/NC-600 delivers the reversible capacity of 265 mAh/g with the test temperature of 60 ℃. More importantly, the flexible B-P/NC-600 is fabricated as anode for the whole battery, delivering the capacity of 90 mAh/g at 1 A/g after 200 cycles. Meanwhile, theoretical calculation further verified that boron and phosphorus co-doping can improve the adsorption capacity of nitrogen carbon materials. The favorable performance of flexible B-P/NC-600 can be ascribed to the nitrogen-rich carbon nanofibers with three-dimensional network matrix for the more active site of boron and phosphorus co-doping. Our work paves the way for the improvement of flexible anodes and wide-operating temperature of sodium-ion batteries by doping approach of much heteroatom.
Precise tumor targeting and therapy is a major trend in cancer treatment. Herein, we designed a tumor acidic microenvironment activatable drug loaded DNA nanostructure, in which, we made a clever use of the sequences of AS1411 and i-motif, which can partially hybridize, and designed a simple while robust DNA d-strand nanostructure, in which, i-motif sequence was designed to regulate the binding ability of the AS1411 aptamer to target tumor. In the normal physiological environment, i-motif inhibits the targeting ability of AS1411. In the acidic tumor microenvironment, i-motif forms a quadruplex conformation and dissociates from AS1411, restoring the targeting ability of AS1411. Only when acidic condition and tumor cell receptor are present, this nanostructure can be internalized by the tumor cells. Moreover, the structure change of this nanostructure can realize the release of loaded drug. This drug loaded A-I-Duplex DNA structure showed cancer cell and spheroid targeting and inhibition ability, which is promising in the clinical cancer therapy.
In-situ enhanced bioreduction by functional materials is a cost-effective technology to remove chlorinated hydrocarbons in groundwater. Herein, a novel polydopamine (PDA)-modified biochar (BC)-based composite containing nanoscale zero-valent iron (nZVI) and poly-l-lactic acid (PLLA) (PB-PDA-Fe) was synthesized to enhance the removal of 1,1,1-trichloroethane (1,1,1-TCA) in simulated groundwater with actual site sediments. Its impact on functional microbial community structure in system was also investigated. The typical characterizations revealed uniform dispersion of PLA and nZVI particles on the BC surface, being smoother after PDA coating. The composite exhibited a significantly higher performance on 1,1,1-TCA removal (82.38%, initial concentration 100 mg/L) than Fe-PDA and PB-PDA treatments. The diversity and richness of the microbial community in the composite treatment consistently decreased during incubation due to a synergistic effect between PLLA-BC and nZVI. Desulfitobaterium, Pedobacter, Sphaerochaeta, Shewanella, and Clostridium were identified as enriched genera by the composite through DNA-stable isotope probing (DNA-SIP), playing a crucial role in the bioreductive dechlorination process. All the above results demonstrate that this novel composite selectively enhances the activity of microorganisms with extracellular respiration functions to efficiently dechlorinate 1,1,1-TCA. These findings could contribute to understanding the responsive microbial community by carbon-iron composites and expedite the application of in-situ enhanced bioreduction for effective remediation of chlorinated hydrocarbon-contaminated groundwater.
In this work, we developed plasmonic photocatalyst composed of CuPd alloy nanoparticles supported on TiN, the optimized Cu3Pd2/TiN catalyst shows excellent conversion (> 96%) and selectivity (> 99%) for Heck reaction at 50 ℃ under visible light irradiation. By in-situ spectroscopic investigations, we find that visible light excitation could achieve stable metallic Cu species on the surface of CuPd alloy nanoparticles, thereby eliminating the inevitable surface oxides of Cu based catalyst. The in-situ formed metallic Cu species under irradiation take advantage of the strong interactions of Cu with visible light, and manifest in the localized surface plasmon resonances (LSPR) photoexcitation. Visible light excitation could further promote the charge transfer between catalytic Pd component and the support TiN, resulting in electron-rich Pd sites on CuPd/TiN. Moreover, light excitation on CuPd/TiN generates strong chemisorption of iodobenzene and styrene, favoring the activation of reactants for Heck reaction. DFT calculations suggest that electron-rich CuPd sites ideally lower the activation energy barrier for the coupling reaction. This work provides valuable insights for mechanistic understanding of plasmonic photocatalysis.
As battery technology evolves and demand for efficient energy storage solutions, aqueous zinc ion batteries (AZIBs) have garnered significant attention due to their safety and environmental benefits. However, the stability of cathode materials under high-voltage conditions remains a critical challenge in improving its energy density. This review systematically explores the failure mechanisms of high-voltage cathode materials in AZIBs, including hydrogen evolution reaction, phase transformation and dissolution phenomena. To address these challenges, we propose a range of advanced strategies aimed at improving the stability of cathode materials. These strategies include surface coating and doping techniques designed to fortify the surface properties and structure integrity of the cathode materials under high-voltage conditions. Additionally, we emphasize the importance of designing antioxidant electrolytes, with a focus on understanding and optimizing electrolyte decomposition mechanisms. The review also highlights the significance of modifying conductive agents and employing innovative separators to further enhance the stability of AZIBs. By integrating these cutting-edge approaches, this review anticipates substantial advancements in the stability of high-voltage cathode materials, paving the way for the broader application and development of AZIBs in energy storage.
Benzotriazole (BTA)-based A2-A1-D-A1-A2 type wide-bandgap (WBG) non-fullerene acceptors (NFAs) have shown promising potential in indoor photovoltaic, and in-depth investigation of their structure-property relationship is of great significance. Herein, we explored the chlorination effect of the side chain on the terminals. We introduced Cl atoms into the benzyl side chains in parent BTA5 to synthesize two NFAs, BTA5-Cl with mono-chlorinated benzyl groups and BTA5-2Cl containing bi-chlorinated benzyl groups. We chose D18-Cl with deep-energy levels and strong crystallinity to pair with these three acceptors, affording high photovoltage and photocurrent. With the stepwise chlorination, the open-circuit voltage (VOC) values decrease from 1.28, 1.22, to 1.20 V, while the corresponding power conversion efficiencies (PCEs) improve from 5.07%, 9.15%, to 10.96%. Compared with BTA5-based OSCs, introducing Cl atoms downshifts the energy levels and slightly increases the non-radiative energy loss (0.14 < 0.17 < 0.19 eV), resulting in a sequential decrease in VOC. However, more chlorine atom replacements produce more effective exciton dissociation, higher charge transfer, and balanced carrier mobility in the blend films, ultimately achieving better PCEs. This work indicates that chlorination of the benzyl group on the terminals can improve the device's performance, implying good application potential in indoor photovoltaics.
The high conductivity of electrocatalyst can eliminate the Schottky energy barrier at the interface of heterogeneous phases during an electrocatalytic reaction and accelerate the rapid electron transfer to the catalytic active center. Therefore, the electronic conductivity is a vital parameter for oxygen reduction reaction (ORR). Covalent triazine frameworks (CTFs) have shown great potential application as electrocatalysts in ORR with a merit of the diverse building blocks. However, the intrinsic low conductivity and high impedance of CTFs could be significant setbacks in electrocatalytic application. Herein, CTFs were constructed by introducing F and N co-modification for efficient 2e− ORR. Compared with the pristine CTF, the co-presence of F, N could increase the conductivity obviously by 1000-fold. As a result, F-N-CTF exhibits enhanced catalytic performance of H2O2 generation and selectivity towards reaction pathways. This work reveals the importance of conductivity optimization for CTFs and provides guidance for designing high conductivity non-metallic organic semiconductor catalysts for 2e− ORR.
Disulfidptosis, a novel mechanism of programmed cell death through the disruption of tumor metabolic symbiosis (TMS), has showed tremendous potential in cancer therapy. However, the efficacy of disulfidptosis is limited by poor permeability of drugs in solid tumors. Herein, hydrogen sulfide (H2S) and near-infrared (NIR) light-driven nanomotors (denoted as HGPP) have been constructed to efficiently penetrate tumors and induce disulfidptosis. HGPP demonstrate glutathione (GSH)-responsive release of H2S, which combined with NIR light-induced photothermal effect drive HGPP movement to facilitate deep tumor penetration. The released H2S induces tumor acidosis and disrupts TMS, where disulfide accumulation following cell starvation leads to disulfidptosis. In addition, HGPP induce hepatoma specific cellular uptake and catalyze the conversion of glucose and oxygen to produce hydrogen peroxide (H2O2), leading to glucose starvation. Overall, this study has developed a multifunctional Janus nanomotor that provides a novel strategy for disulfidptosis-based solid tumor therapy.
Photocatalytic overall pure water splitting is a promising method for generating green hydrogen energy under mild conditions. However, this process is often hindered by sluggish electron-hole separation and transport. To address this, a step-scheme (S-scheme) B-doped N-deficient C3N4/O-doped C3N5 (BN-C3N4/O-C3N5) heterojunction with interfacial B-O bonds has been constructed. Utilizing Pt and Co(OH)2 as co-catalysts, BN-C3N4/O-C3N5 S-scheme heterojunction demonstrates significantly enhanced photocatalytic activity for overall pure water splitting under visible light, achieving H2 and O2 evolution rates of 40.12 and 19.62 µmol/h, respectively. Systematic characterizations and experiments revealed the performance-enhancing effects of the enhanced built-in electric field and the interfacial B-O bonding. Firstly, the strengthened built-in electric field provides sufficient force for rapid interfacial electron transport. Secondly, by reducing the transport energy barrier and transfer distance, the interfacial B-O bonds facilitate rapid recombination of electrons and holes with relatively low redox potential via the S-scheme charge-transfer route, leaving the high-potential electrons and holes available for H+ reduction and OH− oxidation reactions. Overall, the photocatalytic efficiency of BN-C3N4/O-C3N5 S-scheme heterojunction was significantly improved, making it a promising approach for green hydrogen production through overall pure water splitting.