Experimental and DFT Insights on Microflower g-C<sub>3</sub>N<sub>4</sub>/BiVO<sub>4</sub> Photocatalyst for Enhanced Photoelectrochemical Hydrogen Generation from Lake Water
Mohamad Fakhrul Ridhwan Samsudin, Habib Ullah, Robabeh Bashiri, Norani Muti Mohamed, Suriati Sufian, Yun Hau Ng
Abstract
Herein, an experimental and density functional theory (DFT) analysis of the composite g-C3N4/BiVO4 microflower photocatalysts are comprehensively discussed. A remarkable photoelectrocatalytic solar hydrogen production has been observed for the as-developed photocatalysts, with different loading amounts of g-C3N4 (0.1, 0.4, 0.8, and 1.2 wt %), using lake water without the addition of sacrificial reagents. The 0.8 wt % g-C3N4/BiVO4 microflower photocatalyst evinced remarkable photoelectrocatalytic activity of 21.4 mmol/h of hydrogen generated in comparison to other samples with an AQE of 4.27% at 420 nm. In addition, the photocurrent density of 0.8 wt % g-C3N4/BiVO4 microflower was 2-fold higher than that of pure BiVO4. This was attributed to its better crystallinity and optical properties, confirmed from XRD and DR-UV–vis analysis. The DFT analysis further corroborated that the efficient photocharge carrier separation and limited photocharge carrier recombination corresponded to the synergistic effect of the band offset and built-in electric field.