Integrating ZnO with fibrous silica zirconia p-n heterojunction for effective photoredox of hexavalent chromium and congo red by Hassan, Nurul Sahida, Abdul Jalil, Aishah, Aldeen, E. M. Sharaf, Bahari, Mahadi, Teh, L. P., Rajendran, Saravanan, Che Jusoh, N. W., Razali, Nurul Aini