Boron doped RGO from discharged dry cells decorated Niobium pentoxide for enhanced visible light-induced hydrogen evolution and water decontamination

Abstract

Upgradation in technology leads to the accumulation of a large amount of electronic waste and causes serious issues in the environment. Discharged dry cells are one such waste that needs proper monitoring. The present work deals with the synthesis of boron-doped reduced graphene oxide (BRGO) from graphite derived from dry cells. Nb2O5 (NbO) nanoflakes were decorated with BRGO. Structural and morphological characterizations confirm the formation of NbO-BRGO. NbO-BRGO showed enhanced photocatalysis compared to pristine BRGO and NbO. The photocatalytic H2 evolution was found to be 1742, 1216 and 855 µmol in the presence of NbO-BRGO, NbO and BRGO, respectively. The effect of sacrificial agents was studied and found TEOA to exhibit the highest activity. NbO-NBRO was further evaluated for the degradation of crystal violet (CV) dye under different light sources and was found to degrade 97.6 % under solar light. The reaction conditions like the effect of pH, catalyst dosage, and initial concentration were optimized carefully. The optical, electronic and photoelectrochemical characterizations of the materials indicate the decreased bandgap (2.70 eV), enhanced separation of photoexcited electrons and holes and superior current response in NbO-BRGO. The mechanism of photocatalysis has been predicted from LC-MS analysis insights. The NbO-BRGO exhibit good stability in the experiments performed under the light. The results indicate the suitability of the NbO-BRGO material for light-driven catalytic activity for energy production and environmental remediation.