Described herein is the synthesis, characterization and photoelectrochemical behavior of a novel composite consisting of nanolayered manganese-calcium oxide (MCO) and mesoporous tungsten trioxide (WO3). The samples were characterized by transmission electron microscopy (TEM), and X-ray diffraction (XRD). The results demonstrated that superior interfacial contacts had been formed between WO5 and MCO. UV-vis diffuse reflectance spectroscopy (DRS), photoelectrochemical characterization, and incident photon-to-current efficiency (IPCE) revealed an enhanced light harvesting and effective electron-hole separation. A photoelectrochemical (PEC) cell composed of the n-type MCO/WO3 as a photoanode and platinum sheet as a counter electrode was assembled to estimate the feasibility for overall water splitting under a solar simulator illumination. The photocatalytic hydrogen and oxygen production from the photochemical cell with optimized photocatalyst (MCO/WO3-9) under 2 h simulated solar light irradiation was 1.9 mu mol and 0.7 mu mol, respectively, at low extra bias (0.90 V vs. RHE). Our investigation suggests that coupling MCO with n-type semiconductor WO3 as photoanode is a promising method to improve the activity of overall water splitting to generate oxygen and hydrogen. (C) 2018 Elsevier Inc. All rights reserved.