Phenol degradation on Pr6O11 surface under UV-A light. Synergistic photocatalysis by semiconductors

Phenol degrades on the surface of Pr6O11, an insulator, under UV-A light and the degradation rate increases linearly with phenol concentration and photon flux but decreases linearly with pH. The degradation efficiency is higher with UV-C light than with UV-A light. While TiO2, Fe2O3, CuO, ZnO, ZnS, Nb2O5 and CdO particles individually photocatalyze the degradation each semiconductor exhibits synergistic effect, an enhanced photodegradation, when present along with Pr6O11 suggesting hole-transfer from illuminated semiconductors to phenol adsorbed on Pr6O11 during collision.