Tailoring the morphological structure of BiVO4 photocatalyst for enhanced photoelectrochemical solar hydrogen production from natural lake water

Solar hydrogen production via natural lake water was investigated via monoclinic bismuth vanadate (BiVO4) photocatalyst in a tandem photoelectrochemical cell (PEC), which was made up via integrating a PEC system with a dye-sensitized solar cell (DSSCs) in a series. Herein, the visible-light-driven BiVO4 photocatalysts were synthesized via a simple hydrothermal treatment reaction. A mathematical representation for optimizing the synthesizing condition of BiVO4, namely pH and the hydrothermal temperature was successfully generated via response surface methodology (RSM). The BiVO4 sample prepared at pH = 1.96 and hydrothermal treatment at 120 degrees C (Run 4) exhibited remarkable photocatalytic hydrogen performance of 9.52 mmol/h within 7 h. In addition, the observed photocurrent density and photoconversion efficiency were 5.66 mA/cm(2) at 0.7 V and 0.056%, respectively. The profound performance observed was attributed to the low photocharge carrier resistance and a more negative flat band potential for PEC water splitting system. This work demonstrates the feasibility of producing hydrogen from abundant natural lake water via BiVO4 photocatalyst.