Yttrium-Induced Regulation of Electron Density in NiFe Layered Double Hydroxides Yields Stable Solar Water Splitting

In situ catalyst regeneration of NiFe-based oxygen evolution catalyst (OEC) has been recognized as one of the best approaches for photocorrosion inhibition on water splitting photoelectrodes. However, it generally suffers from laborious multistep procedures to obtain a controllable film. Herein, we use an electron density modulation to synthesize a stable NiFeY layered double hydroxide (LDH) OEC and then deposit this OEC on BiVO4 as photoanodes. The incorporation of Y modifies the chemical environment of Ni and reduces the bandgap of NiFe LDH, enhancing the electrocatalytic/photoelectrochemical performance. Importantly, Y insertion in NiFe LDH remarkably reduces the surface recombination of the BiVO4/cocatalyst system, thereby establishing a much high stability to the photocatalyst than in conventional NiFe OEC/BiVO4 approaches.