摘要： TixFe1-xOy shells, in-situ formed from thermal treatment of a Ti-containing metal organic framework, NH2-MIL-125(Ti), significantly boost the photoelectrochemical water oxidation efficiency of Fe2O3 nanorod cores. The NH2-MIL-125(Ti) was coated on the surface of the Fe2O3 nanorods with a solvothermal process, followed by a two step calcination to afford the TixFe1-xOy shell/Fe2O3 core nanorod arrays. The TixFe1-xOy shell/Fe2O3 core nanorod array electrode exhibited much improved photoelectrochemical activities over the pristine Fe2O3 nanorod array electrode, boosting photo-current densities to 26.7 folds of that achieved by the pristine Fe2O3 nanorod array electrode at 1.23 V (vs. RHE) under illumination of simulated sun light of AM 1.5G. The success may be attributed to the much enhanced charge separation enabled by the hole trapping heterojunction of TixFe1-xOy shell/Fe2O3 core. The photoelectrochemical stability of the TixFe1-xOy shell/Fe2O3 core nanorod array electrode was excellent, retaining 98.9% of the initial photo-current density after a 5 hr continuous operation. This work is the first demonstration of MOF derived core-shell heterojunction for large improvements of PEC water splitting efficiencies, and can be readily extended to a wide range of catalyst design.