Revealing the impact of significant improvement in the solar-driven water oxidation of 1-D Co2P2O7 modified BiVO4 photoanode

Abstract

In this report, we have prepared 1-D Co2P2O7 nanostructures, which works as an efficient oxygen evolution catalyst when loaded over BiVO4 through drop casting followed by annealing procedures. Different structural, morphological, elemental and optical analysis confirms the deposition of Co2P2O7 over BiVO4. The optimum loading of Co2P2O7 shows, 4.5 times higher value of the photocurrent densities than pristine BiVO4 photoanode in the 0.5 M of Na2SO4 electrolyte. Apart from this, the oxygen vacancies within the BiVO4 /Co2P2O7 structure have been increased due to the loading of Co2P2O7 over BiVO4. Well optimized BiVO4 /Co2P2O7 photoanode shows:- (i) drastic cathodic shift in the initial potential of the oxygen evolution analyzed by Butler plot, (ii) incident photon to current conversion enhanced by 4.6 times, (iii) Mott-Schottky analysis shows shifting in the flat band with very high donor density, (iv) high charge injection efficiency improved by 3 times and (v) exceptional photostability. At the end in depth photoelectrochemical impedance spectroscopic studies have also been done to understand the influence of loading of 1D-Co2P2O7 over BiVO4. The outcomes of this research open the way for a simple plan to achieve the ideal co-catalyst/semiconductor coupling necessary for effective solar fuels manufacturing.