Hydrothermal synthesis of C doped ZnO nanoparticles coupled with BiVO4 and their photocatalytic performance under the visible light irradiation.

For the first time, C-ZnO/BiVO 4 heterostructured nanocomposite has been synthesized from BiVO 4 and carbon-doped ZnO nanoparticles. X-ray diffraction (XRD) study showed themonoclinic scheelite structure of BiVO 4 and the hexagonal wurtzite structure of ZnO in the C-ZnO/BiVO 4 composite. Field emission scanning electron microscope (FESEM) and transmission electron microscope (TEM) images revealed the spherical nanoparticles of size 20 to 30 nm for C-ZnO. The band gap of the ZnO has turned towards the visible region by doping with carbon as well as a composite formation with visible light active material BiVO 4. The chemical states of Zn, O, C and Zn, O, C, Bi, V species in C-ZnO, and C-ZnO/BiVO 4 composite respectively were confirmed by X-ray photoelectron microscopy (XPS) analysis. Also, the XPS spectra showed the significant peaks shift in the electronic states of Zn, O, and C for the heterojunction composite. The suppression of the electron-hole recombination rate was confirmed from the quenching of photoluminescence (PL) intensity for the composite. The adsorption study has performed, and the experimental results fit well with the Langmuir isotherm model for understanding the catalytic activity of the samples. The possible Z -scheme photocatalytic mechanism of the C-ZnO/BiVO 4 nanocomposite photocatalyst has proposed. The nanocomposite exhibited the enhanced catalytic activity with the higher degradation rate constant of 0.050 min−1 for 50 min irradiation of visible light compared with their counterparts. • C-ZnO/BiVO 4 nanocomposite has higher pseudo first order kinetic rate constant. • The band gap of ZnO can be tuned into visible light via the formation of composite. • The influence of C and BiVO 4 in ZnO and their catalytic performances against MB dye. • The formation of hetero-junction suppressed the electron–hole recombination rate. [ABSTRACT FROM AUTHOR]