Abstract
In recent decades, clean energy and solar fuels have gained extensive popularity because of the ongoing environmental and energy crisis. Oxygen evolution reaction (OER) has the capability to offset the ongoing crisis. OER is one of the key electrocatalysis technologies for the development of renewable energy conversion and storage systems like water splitting, metal-air batteries, and fuel cells. This research focuses on developing a semiconductor-polymer hybrid system with improved photocatalytic capabilities to increase the efficiency of OER reaction.
The semiconductor of interest was BiVO 4 due to its ability to harvest visible sunlight. The limiting factor of BiVO 4 is its high electron-hole recombination yield. Therefore, the BiVO 4 was doped with Molybdenum (Mo) and combined with Co-C 3 N 3 S 3 coordination polymer to maximize electron-hole separation and increase free electron mobility.
Comparative photochemical studies were performed to investigate the effects of different concentrations of Mo dopant, which helped to optimize the dopant concentration. The BiVO 4 was formed on FTO glass by chemical transformation of electrodeposited BiOI with the use of Vo(acc) 2 precursor and annealing it at a temperature of 450 °C.
With the obtained experimental data, it was observed that at very low concentrations of Mo dopant there is an improvement of photocurrent intensity compared to pristine BiVO 4 , but at higher concentrations of Mo, the photocurrent decreases because of irreversible changes in the crystallographic structure. Strong improvement of water oxidation was also observed with the use of Co-C 3 N 3 S 3 polymer deposited on the top of BiVO 4 . Therefore it can be concluded that the developed hybrid system is a good catalyst for water oxidation.