Fazhi Zhang

The selective electrooxidation of glycerol (GLY) to formic acid is a promising route for biomass valorization, but non-noble catalysts often suffer from poisoning, competitive OH^-/substrate adsorption, and limited light utilization. Herein, we report a sand-rose-like Cu₂S/Ni₃S₂ heterostructure grown on nickel foam, in which cetyltrimethylammonium bromide (CTAB) regulates the Cu₂S morphology and interfacial electronic structure. The resulting catalyst achieves 10 mA cm^-2 at 1.18 V vs RHE for glycerol electrooxidation and maintains a total FE above 90% over five cycles. Under illumination, the formic acid production rate rises from 115.9 to 150.7 μmol cm^-2 h^-1. Combined electrochemical and spectroscopic results indicate that the Cu₂S/Ni₃S₂ heterostructure promotes charge transfer, the CTAB-regulated morphology increases the electrochemically active surface area (ECSA), and illumination improves interfacial reaction kinetics while suppressing the competing oxygen evolution reaction (OER). Operando spectroscopy further suggests that NiOOH is the active oxidizing species and that glycerol is converted to formic acid through sequential oxidation and C-C bond cleavage steps. This work provides an effective strategy for coupling heterostructure engineering and photoassisted electrocatalysis to enhance selective glycerol upgrading.

The poor intrinsic electronic conductivity of copper-based oxide materials limits their development for aqueous electrochemical energy storage devices (AEESDs). Herein, we developed a self-supporting vanadium-doped Cu_xO nanorod array AEESD via in situ transformation using a template precursor and modification with vanadium. Theoretical and experimental analyses illustrate that partial vanadium isomorphic substitution at copper sites can successfully modulate the electronic and lattice structure of the pristine materials, thereby driving electron transfer and resulting in enhanced electrical conductivity and reaction kinetics for energy storage. An AEESD constructed with a V-Cu_xO nanorod array negative electrode shows desirable electrochemical performance, with a high energy density of 1.26 mWh cm⁻² at a power density of 8.50 mW cm⁻² and 0.71 mWh cm⁻² at 85 mW cm⁻². The AEESD can effectively power LED lighting. This work provides novel insights into how modulation of the crystal structure of copper-based oxides can enhance their electrochemical performance.

NiFeCuP is synthesized by the topotactic transformation of layered double hydroxide (LDH) precursors. Crystal surface engineering of the bi-functional catalyst NiFeCuP can enhance the OER and HER performance via crystal surface engineering.

Regulating the electronic structure of MoS₂ by constructing cationic vacancies is an effective method to activate and improve its intrinsic properties. Herein, we synthesize the MoS₂-based composite with abundant single atomic Mo cation vacancies through uniformly loading nickel-cobalt-Prussian blue analogues (NiCoPBA) (NiCoPBA-MoS₂-V_Mo) by immersing a single Ni atom-decorated MoS₂ (Ni-MoS₂) into K₃[Co(CN)₆] solution. Subsequently, NiCoP-MoS₂-V_Mo with improved conductivity is obtained by phosphating the composite as a high-efficiency hydrogen evolution reaction (HER) catalyst. Experiments and theoretical calculations indicate that the electrons of NiCoP are spontaneously transferred to the substrate MoS₂-V_Mo nanosheets in NiCoP-MoS₂-V_Mo, and the moderately oxidized NiCoP is beneficial to the adsorption of OH*. Meanwhile, the mono-atomic Mo cation vacancies of the catalyst modulate the electronic structure of S, optimizing the adsorption of hydrogen in the reaction process. Therefore, NiCoP-MoS₂-V_Mo has enhanced chemical adsorption for H* (on MoS₂-V_Mo) and OH*(on NiCoP), expediting the water-splitting step and HER catalysis, and benefiting from the regulation of the electronic structure induced by the construction of metallic Mo vacancies in MoS₂, the as-prepared catalyst displays an overpotential of only 67 mV at 10 mA cm^-2 with long-term stability (no current decay over 20 h). This work affords not only a kind of efficient HER catalysts but also a new valuable route for developing inexpensive and high-performance catalysts with single atomic cation vacancies.