Fabrication of Mesoporous Co₃O₄ from LP-FDU-12 via Nanocasting Route and Effect of Wall/Pore Size on Their Magnetic Properties

Highly ordered mesoporous Co₃O₄ nanostructures were prepared using LP-FDU-12 as hard templates. By changing the hydrothermal temperature or by the acid treatment of the LP-FDU-12 template, Co₃O₄ replicas with different cell parameters and wall thicknesses have been obtained. The structure and textural characteristics of both LP-FDU-12 and Co₃O₄ replicas were investigated by X-ray diffraction, transmission electron microscopy, and N₂ adsorption–desorption isotherm analysis. The cell parameter and wall thickness of a mesoporous Co₃O₄ have been varied systematically within the ranges 30.4–33.9 and 24.8–18.2 nm, respectively, and the materials exhibit surface areas in the 29.6–52.9 m² g^–1 range, while preserving a highly ordered 3D pore structure and highly crystalline walls. Most importantly, magnetic studies show that the factors which affect the magnetic behavior in the Co₃O₄ nanosphere system are not only the sphere size but also the space-filled parameter at the nanoscale

BiVO₄‑Based Heterojunction Photocathode for High-Performance Photoelectrochemical Hydrogen Peroxide Production

Photoelectrochemical (PEC) cells provide a promising solution for the synthesis of hydrogen peroxide (H2O2). Herein, an integrated photocathode of p-type BiVO4 (p-BVO) array with tetragonal zircon structure coupled with different metal oxide (MOx, M = Sn, Ti, Ni, and Zn) heterostructure and NiNC cocatalyst (p-BVO/MOx/NiNC) was synthesized for the PEC oxygen reduction reaction (ORR) in production of H2O2. The p-BVO/SnO2/NiNC array achieves the production rate 65.46 μmol L–1 h–1 of H2O2 with a Faraday efficiency (FE) of 76.12%. Combined with the H2O2 generation of water oxidation from the n-type Mo-doped BiVO4 (n-Mo:BVO) photoanode, the unbiased photoelectrochemical cell composed of a p-BVO/SnO2/NiNC photocathode and n-Mo:BVO photoanode achieves a total FE of 97.67% for H2O2 generation. The large area BiVO4-based tandem cell of 3 × 3 cm2 can reach a total H2O2 production yield of 338.84 μmol L–1. This work paves the way for the rational design and fabrication of artificial photosynthetic cells for the production of liquid solar fuel