Bio-approach synthesis of nanosilver impregnation on calcium hydroxyapatite by biological activated ammonia from urinary waste

Biological mediated synthesis of RGO-ZnO composites with enhanced photocatalytic and antibacterial activity

In this study, we reported the biological approach to synthesis of ZnO nanorod (NR) on the reduced graphene oxide (RGO) for photocatalytic, antibacterial activity and hydrogen production under sunlight. Bacillus subtilis played a vital role in the production of biogenic ammonia from synthetic urine and utilized for the synthesis of ZnONR on the RGO sheet. The morphological study revealed that RGO sheets displayed a tremendous role in anchoring ZnONR. XRD patterns showed the ZnO crystal phase on the RGO sheets. XPS and Raman spectra confirmed that the bio-hydrothermal method as suitable for GO converted into RGO. The transient photocurrent and I/V measurement are exhibited as an increment on the RGO-ZnONR compared to ZnONR. The RGO-ZnONR composites showed excellent performance with decolorization of MB and textile dyes and efficient control of the E. coli and S. aureus. RGO-ZnONR exhibited remarkable noted as a higher photocatalytic hydrogen evolution rate (940 μmol/h/g_cat) than the ZnONR (369.5 μmol/h/g _cat). As a result of photocatalytic performance to correlate with sunlight intensity was extensively studied. RGO plays an essential role in interface electron transfer from sunlight to ZnONR for enhancing •OH radical formation to cleavage of dye color substance and eradicated bacterial cells.