Phosphate-modified graphitic C3N4 as efficient photocatalyst for degrading colorless pollutants by promoting O-2 adsorption

The photocatalytic activity for degrading gas-phase acetaldehyde and liquid-phase phenol by graphitic carbon nitride could be greatly improved after modification with phosphoric acid, which is attributed to the clear increase in adsorbed O-2 which prolongs the lifetime and enhances the separation of photogenerated charge carriers. This is based on O-2 temperature-programmed desorption curves, steady-state surface photovoltage spectra, and time-resolved surface photovoltage responses.