Visible light driven hydrogen peroxide production by oxygen and phosphorus co-doped CoP-C₃N₄ photocatalyst

Photocatalytic hydrogen peroxide (H2O2) by oxygen and phosphorus co-doped graphitic carbon nitride (C3N4) with cobalt phosphate (CoP) cocatalyst is investigated. The photocatalyst powder of CoP-C3N4 1:n, n = 0-4, n is the weight ratio of cyanuric acid added) was synthesized by melamine cyanurate template method. Characterization of the catalyst was performed by X-ray diffraction analysis, and scanning electron microscopy, X-ray photoemission spectra, and fluorescence decay spectra. Oxygen doping was performed by the melamine and cyanuric acid template method, followed by phosphorus doping of the C3N4 backbone by the introduction of CoP. Co-doping of O and P atom facilitated charge transfer on the C3N4 backbone, while CoP facilitated charge separation at the C3N4 interface. The CoP-C3N4 (1:4) photocatalyst increased H2O2 production rate by 293 % compared to that of the cyanuric acid-free photocatalyst and also achieved the photocatalytic oxygen evolution from water. These results indicate that O,P co-doped CoP-C3N4 can perform sacrificial agent-free hydrogen peroxide under visible light irradiation.