Dual-phase Nb₂O₅(N)/GaN(O) photocatalyst with N doping in Nb₂O₅ and O doping in GaN was synthesized via nitridation and re-oxidation (NRO) of GaNbO₄. The NRO process induced the formation of nanosized heterojunctions between the Nb₂O₅(N) and GaN(O) phase. The utilization of GaNbO₄ as a precursor enhances the nitridation process than pure gallium oxide while retards the oxidation of pure niobium nitride to give an improved doping composite showing a desired bandgap around 2.0 eV with indirect transition. The photocatalyst exhibited very high NO removal efficiency (nearly 100%) under visible-light and very high selectivity (89%) for the formation of ionic species rather than more toxic NO₂, which could be related to the intimate junction between the GaN(O) phase with high conduction band minimum and Nb₂O₅ phase with low valence band maximum for the simultaneous generation of •O₂¯ and •OH radicals, respectively. The NRO process sheds light on the preparation of a nanoscale dual-phase photocatalyst containing nitride and oxide.

通过GaNbO _4的氮化和再氧化（NRO）合成了Nb ₂ O _5中N掺杂和GaN中O掺杂的双相Nb ₂ O ₅（N）/ GaN（O）光催化剂。NRO过程诱导了Nb ₂ O ₅（N）和GaN（O）相之间纳米级异质结的形成。GaNbO ₄的利用作为前驱体，与纯氧化镓相比，前者增强了氮化过程，同时延缓了纯氮化铌的氧化，从而提供了一种改进的掺杂复合材料，该复合材料显示出具有约2.0 eV的带隙并具有间接过渡。该光催化剂在可见光下显示出非常高的NO去除效率（接近100％），并且形成离子物种的选择性非常高（89％），而不是毒性更大的NO ₂，这可能与GaN（ O）相具有最小的导带，而Nb ₂ O ₅相具有的最小价带，可同时产生•O ₂和•OH自由基。NRO工艺为制备包含氮化物和氧化物的纳米级双相光催化剂提供了启示。