Experimental and first principle DFT comprehensions of metal and bimetal modified bismuth titanate for wastewater treatment and CO 2 hydrogenation

Incorporating copper (Cu) and silver (Ag) at the bismuth titanate (BT) surface was carried out via hydrolysis method followed by calcination at 700 °C. Modified BT further tested for the photodegradation of a recalcitrant pollutant Bisphenol-A (BPA), followed by the evaluation of photocatalytic hydrogenation of CO2 for selective production of CO and CH4. Photodegradation studies were remarkable in BT doped with both the metals (labelled “BTCA”) as compared to pristine BT and mono metal modified BT with Cu and Ag. In case of photocatalytic CO2 hydrogenation, BTCA analyte demonstrated a proximal increase in CO2 conversion efficiency, which enhanced up to 39.1% as compared to monometallic doped and pristine BT. CO was the primary product of CO2 reduction, while CH4 was also produced to a lesser level. As CH4 selectivity increased, surface normalised CO2 conversion rates declined. This result was attributed to the difference in the number of electrons required to convert CO2 to CO or CH4. In our previous work of pristine BT, methane selectivity was only 0.1–0.2% of the overall CO2 conversion. Hence, present findings are based on the modification of BT with copper and silver, for the evaluation of electron transfer and abundance for enhanced selectivity for CH4.