Defect Regulating of Few-Layer Antimonene from Acid-Assisted Exfoliation for Enhanced Electrocatalytic Nitrogen Fixation

Self-Assembly Synthesis of Oxygen and Sulfur Co-Doped Porous Graphitic Carbon Nitride Nanosheets for Boosting CO2 Photoreduction

Graphitic carbon nitride (CN) has garnered considerable attention in the field of visible-light CO2 photoreduction, but its efficiency remains limited by the intrinsic π-conjugated skeleton. Here, O and S were co-doped CN (O, S/CN) by a facile "hydrolysis + calcination" approach to modulate the physicochemical and electronic structure. Distinctive from S doped CN (SCN), O, S/CN owned porous layer structure with several nanosheets and less SO4 2- groups on the surface. The amount of heteroatom-doping was achieved by changing the hydrothermal temperature. The optimum O, S/CN-80 achieved moderate CO production rate of 1.29 μmol g-1 h-1, which was 3.79 times as much as SCN (0.34 μmol g-1 h-1). The O and most S atoms were substitutionally doped and the effect of S doped state on the improved efficiency of CO generation in O, S/CN was also explored based on the theoretical calculations. This work provides an inspiration to develop efficient dual-doped CN photocatalysts for photocatalytic CO2 reduction.

Accelerating the electron-transfer of nitrogen electro-fixation through assembling Fe nanoparticles into Fe nanochains

Electrochemically synthesizing NH3 via N2 is a facile and sustainable approach that involves multistep electron and proton transfer processes. Thus, consecutive electron and proton transfer is necessary. Here, a universal method with the assistance of magnetic stirring that can assemble Fe, Co, and Ni nanoparticles into nanochains is developed. Notably, the Fe nanochain, composed of amorphous Fe nanoparticles, facilitates electron and proton transfer, resulting in an enhanced NH3 yield (92.42 μg h-1 mg-1) and faradaic efficiency (20.02%) at -0.4 V vs. RHE during the electrochemical reduction of N2. This work offers new insight into designing tandem electrocatalysts.

Defect engineering of two-dimensional materials for advanced energy conversion and storage

In the global trend towards carbon neutrality, sustainable energy conversion and storage technologies are of vital significance to tackle the energy crisis and climate change. However, traditional electrode materials gradually reach their property limits. Two-dimensional (2D) materials featuring large aspect ratios and tunable surface properties exhibit tremendous potential for improving the performance of energy conversion and storage devices. To rationally control the physical and chemical properties for specific applications, defect engineering of 2D materials has been investigated extensively, and is becoming a versatile strategy to promote the electrode reaction kinetics. Simultaneously, exploring the in-depth mechanisms underlying defect action in electrode reactions is crucial to provide profound insight into structure tailoring and property optimization. In this review, we highlight the cutting-edge advances in defect engineering in 2D materials as well as their considerable effects in energy-related applications. Moreover, the confronting challenges and promising directions are discussed for the development of advanced energy conversion and storage systems.

An electrochemical impedance aptasensor based on selenomolybdate nanodot/antimonene hybrid for platelet-derived growth factor-BB

The aim of the present study was to design a unique bioelectrode for the quantitative analysis of a potential cancer biomarker, platelet-derived growth factor-BB (PDGF-BB), which can be used for the early detection of cancer. We report the fabrication of succinic acid-capped selenomolybdate polyoxometalate nanodots, POM (SA), decorated antimonene hybrid film on glassy carbon as a suitable bioelectrode. Antimonene nanosheets, synthesized by the chemical exfoliation of antimony provided a large surface area for the symmetric dispersal of POM (SA) nanodots, resulting in site-specific covalent immobilization of the aptamer, PDGF-BB. A comprehensive electrochemical immunosensing investigation was performed on the electrode for sensing of a target antigen, Ag-PDGF-BB. The sensitivity, selectivity, and reproducibility of the bioelectrode were investigated using a best-fit equivalent circuit model that fitted the impedance response. The bioelectrode showed a linear impedimetric response in a broad range for Ag-PDGF-BB (10 pM to 100 nM in pH 7.4 PB) with a limit of detection of 3.5 pM and sensitivity of 80 Ω cm² per decade. The response sensitivity of the POM(SA)/antimonene hybrid based bioelectrode toward PDGF-BB was approximately ∼1.8-fold higher than that of the POM(SA) only modified bioelectrode. The dissociation constant of immunoreaction between the aptamer-functionalized bioelectrode and target Ag-PDGF-BB was 76 nM, indicating a high binding affinity between the aptamer PDGF-BB and target Ag-PDGF-BB on the electrode surface.

Efficient visible light driven degradation of antibiotic pollutants by oxygen-doped graphitic carbon nitride via the homogeneous supramolecular assembly of urea

Graphitic carbon nitride (CN), as a non-metal material, has emerged as a promising photocatalyst to address environmental issues with the favorable band gap and chemical stability. The porous oxygen-doped CN nanosheets (CNO) were synthesized by an ecofriendly and efficient self-assembled approach using a sole urea as the precursor. The CNO photocatalysts were derived from the hydrogen-bonded cyanuric acid-urea supramolecular complex, which were obtained by pretreatment of urea at high temperature and pressure. The homogeneous supramolecular assembly was advantageous to the formation of uniform porous and oxygen-doped CN nanosheets. The formation process of the supramolecular intermediate and the CNO nanosheets were investigated. Moreover, doping amount of O in CNO could be controlled by the time of the high-pressure thermal polymerization of urea. The characterization results shown that the O atoms were successfully doped into the framework of CN by substitution the N atoms to form the C-O structures. The obtained CNO photocatalysts demonstrated the excellent visible-light photocatalytic performances for sulfamerazine (SMR) degradation, which was ascribed to synergistic interaction of porous structure and O doping. The degradation intermediates of SMR were identified and the degradation pathway were also proposed. Furthermore, density functional theory (DFT) calculations proved that O doping changed the electronic structure of CN, resulting in more easier to activate O₂. This work provides a novel perceptive for the development of high-performance nonmetal photocatalysts by using the homogeneous supramolecular assembly, which exhibits great potential in the environmental treatment.