Electricity-driven water splitting is considered as a cost-effective and environmentally friendly way to produce hydrogen, but the anodic oxygen evolution reaction (OER) has largely limited its industrial application. High-efficiency electro-oxidation of benzylamine replacing the OER to promote hydrogen production is crucial but challenging. Herein, we demonstrate NiV-layered double hydroxides for the selective oxidation of benzylamine via the introduction of high valence vanadium into α-Ni(OH)2 (a typical OER catalyst). Benefiting from the vanadium doping, the NiV-LDH electrode exhibits superior activity and selectivity for the benzylamine oxidation reaction (BOR). In particular, NiV-LDH requires an ultra-low potential of 1.33 V vs. RHE to achieve a current density of 10 mA cm−2 and exhibits ∼99% selectivity for benzonitrile production over a wide potential range. Reaction mechanism studies indicate that the introduction of vanadium changes the electronic state of NiV-LDH/NF and the Lewis acidic sites on the surface, promoting the conversion of benzylamine. Furthermore, a NiV-LDH based two-electrode electrolyzer that coupled the BOR with the HER can deliver 10 mA cm−2 at a voltage of 1.55 V, which can reduce the cell voltage by 240 mV relative to that of conventional overall water splitting.
Ammonium phosphate ((NH4)3PO4) has been first used as a surface treatment reagent for Li-rich cathode materials. Compared to the conventional surface treatment, the samples treated with (NH4)3PO4 exhibit an ultra-high initial Coulomb efficiency of 98.0% and excellent cycling stability. This is mainly attributed to the simultaneous construction of surface integrated structures, including oxygen vacancies, spinel phases, and Li3PO4 coating. This study demonstrates the effectiveness of ammonium phosphate surface treatment and provides a new idea for designing other cathode materials.