Improving Oxygen Reduction Reaction Performance of Pt by a N‑Doping Strategy and Inducing Tensile Strain of Nanoparticles

The oxygen reduction reaction (ORR) plays a key role in improving the efficiency of energy-storage devices, and Pt nanoparticles anchored in carbon support are one of the most efficient electrocatalysts for ORR. However, Pt falling off the carbon carrier seriously affects the catalytic performance. In this work, we report an innovative Lewis-acid-doping strategy to design an efficient N-doping Pt/N/C catalyst, the special adsorption mechanism of the Pt precursor enhances the ability of the catalyst to anchor N atom, as well as the binding force between Pt nanoparticles and the substrate. N-doping within Pt lattice induces tensile strain and enhances the ORR activity and stability of the catalyst, the half-wave potential of Pt/N/C exhibits a positive shift of 50 mV relative to that of commercial JM Pt/C. This work presents an innovative N-doping strategy to prepare efficient electrocatalysts with defects, indicating a promising potential for the practical applications

Hierarchically Porous, Superhydrophobic PLLA/Copper Composite Fibrous Membranes for Air Filtration

Epidemics such as pulmonary tuberculosis and pertussis can spread quickly through the air in enclosed or small spaces. Most of these diseases are caused by various bacteria. In hospitals, nursing homes, and biology laboratories, the requirement for air quality is often high. Particulate air filters can remove infectious bacteria from the air, making them a good choice for local ventilation systems to capture and remove bacteria or other pathogenic microbes. With high surface area, electrospun poly(l-lactic acid) (PLLA) fibrous membranes have the ability to capture small particles like bacteria. Moreover, copper has significant antimicrobial properties. In this Letter, we present a hierarchically porous PLLA membrane created through electrospinning and acetone treatment. Additionally, we describe two methods for loading copper particles onto the hierarchically porous PLLA membrane, thereby providing capabilities for capturing and killing bacteria. The experiments demonstrated that the final PLLA/Cu composite fibrous membranes exhibit not only excellent air permeability but also remarkable antimicrobial performance while maintaining bendability and superhydrophobic ability. This study provides a simple process, low energy cost, and environmentally friendly method to produce the copper-coated PLLA membrane, which is especially suitable for potential applications in high-flux filtration equipment in hospitals, nursing homes, and biology laboratories

Boosting Charge Separation and Transfer by Plasmon-Enhanced MoS₂/BiVO₄ p–n Heterojunction Composite for Efficient Photoelectrochemical Water Splitting

The poor separation and significant recombination of electron–hole pairs and slow transfer mobility of charge carriers limit the performance of BiVO₄ for photoelectrochemical (PEC) water splitting. To ameliorate the above problems, a novel integrated Ag-embedded MoS₂/BiVO₄ p–n heterojunction ternary composite electrode is fabricated and applied. Surface plasmon resonance (SPR) of Ag nanoparticles (NPs) by the near-field electromagnetic enhancement or abundant hot electrons injection and p–n heterojunction of MoS₂/BiVO₄ by the built-in electrical potential synergistically boost the electron–hole pair separation, transfer properties and suppress the recombination of the electron–hole pairs. Consequently, the BiVO₄−Ag−MoS₂ electrode among four of the BiVO₄-based electrodes achieves the largest photocurrent density of 2.72 mA cm^–2 at 0.6 V vs RHE, which is 2.44 times higher than that of pure BiVO₄ electrode (0.79 mA cm^–2), and possesses the largest IPCE of 51% at 420 nm. This work proposes a worthy design strategy for a plasmon enhanced p–n heterojunction for efficient PEC water splitting