Micropyramid Si/In2O3/CuO/ZnO photocathode and Ni/BiVO4 photoanode have been synthesized using a magnetron sputtering method with different conditions and characterized for a photoelectrochemical water-splitting process. The as-designed heterojunction of Si/In2O3/CuO/ZnO photocathode successfully induces a facile electron transfer to generate hydrogen in 0.5 M H2SO4. Similarly, Ni/BiVO4 photoanode evolves oxygen in 0.1 M Na2B4O7. Both photoreactions are done under concentrated solar-light irradiation (AM 1.5G, 500 mA/cm2). The analysis shows that IPCE values of photocathode and photoanode reached 40 and 60 % at 300 and 400 nm wavelengths, respectively. Furthermore, the ABPE of photocathode and photoanode achieved 14.9% and 0.8% at 0.21 and 1.15 VRHE, respectively. Photoelectrochemical analysis indicates that half cells of the photocathode and photoanode can reach photocurrents of ∼120 and ∼20 mA/cm2 at 0 and 1.23 VRHE, respectively. The outstanding performances indicate a facile charge transfer during redox reactions at the photocathode and photoanode. In addition, combining the photoelectrodes to form a cell configuration of Si/In2O3/CuO/ZnO//Ni/BiVO4 with a proton exchange membrane generates an unbiased photocurrent of 0.26 mA/cm2 at 0.55 VRHE. The combined cell has been tested for its stability in splitting water molecules into hydrogen and oxygen, indicating a promising result to overcome energy and environmental issues.