Multi-output photoelectrochemical system based on Zn/ZnO using aqueous bismuth tea waste electrolyte to produce hydrogen and electricity

Hydrogen a clean energy, can be produced from organic waste through a photoelectrochemical route. This study develops a photoelectrochemical system to produce hydrogen and electricity using visible light absorption. Zn/ZnO photoanode is a photocatalyst continuously pumps through the external circuit to the ferrous cathode. Basic bismuth nitrate (BBN) heterojunction partner of Zn/ZnO mixed with three variants of tea waste, namely black tea (BT), green tea (GT), and oolong tea (OLT). The elemental morphology of the samples was tested to see the nature of the material changes before and after the reaction. The UV-Vis characterization was conducted to view the light absorption profile of each catalyst. Experimental photoelectrochemical in a double chamber to measure the production of current-voltage and hydrogen-oxygen gas. DFT pseudopots orbital simulation was performed to determine the total LUMO energy in the Zn/ZnO photoanode. The results show that the increase in light absorbance is linearly dependent on the degradation of tea waste. The electron flow force separates the anodic and cathodic space in the electrolyte. Water reduction maximizes the hydrons in the anodic space, while polyethylene controls hydron diffusion flow. Zn/ZnO + BBN + BT absorb blue visible light, which doubles the hydrogen production, while violet light improves the hydrogen production by 4 folds.