Air-condition process for Constructing MeAl-LDHs/rGO (Me = Co, Ni, Fe) hybrids toward efficient oxygene evolution...

Transition-metal-based layered double hydroxides (LDHs) are emerging as one of the most promising candidates with superior oxygen evolution reaction (OER) activity. However, their fabrication under mild conditions remains a significant challenge. Here, we propose a low-cost, high-production-rate strategy for controlled preparation of AlOOH/reduced graphene oxide (rGO) with strong adsorption capacity for transition metal cations, and then in-situ conversion to CoAl-LDH/rGO, NiAl-LDH/rGO and FeAl-LDH/rGO under ambient conditions. Based on Density Functional Theory calculations, it is witnessed that the rational electronic coordination between Co and Al enables the charge absorption by surrounding oxygen atoms, thereby playing a critical role in reducing the adsorption free energy and overpotential of OER intermediates toward efficient OER. Consequently, the resultant CoAl-LDH/rGO hybrids exhibit an overpotential of just 368 mV at the current density of 100 mA/cm², with a low Tafel slope of 43.2 mV/dec. Moreover, under Air Mass 1.5 Global (AM 1.5G) illumination, their solar-to-hydrogen (STH) conversion efficiency of photoelectrochemical system achieves ∼ 11.61 %, with robust operation stability up to 24 h, demonstrating great potential for practical applications as advanced OER catalysts.