Layered double hydroxide modified WO₃ nanorod arrays for enhanced photoelectrochemical water splitting

We synthesize hierarchical WO₃@NiFe-layered double hydroxide (LDH) nanoarrays via a controllable hydrothermal process to prepare WO₃ nanorod arrays followed by electrochemical deposition of layer structured NiFe-LDH. The WO₃@NiFe-LDH photoanodes exhibit superior photoelectrochemical water oxidation performance with lower onset potential and higher anodic photocurrent density than that of the pristine WO₃ photoanode. After decorated with the ultrathin NiFe-LDH nanoflakes with optimized content, the WO₃@NiFe-LDH photoanode displays negative shifted onset potential of 0.06 V and enhanced photocurrent density as high as 1.10 mA cm⁻² at the potential of 1.20 V (vs. SCE). The promising performance is attributed to that WO₃ provides superior framework of photoanodes as well as the prospective light harvesting property. What's more, the NiFe-LDH can act as an efficient oxygen evolution co-catalyst to suppress charge carriers recombination and accelerate the water oxidation kinetics. This strategy develops a fascinating cost-effective approach to promote the efficiency of water splitting.