Designing defect enriched Bi2Ti2O7/C3N4 micro-photo-electrolysis reactor for photo-Fenton like catalytic reaction

Among various advanced oxidation processes, photo-Fenton like catalysis, which couples solar energy with Fenton-like catalysis to generate highly reactive species for wastewater decontamination, has attracted broad interests. However, photo-Fenton catalysts usually suffer from poor pH adaptability, metal leaching and photogenerated charge recombination. Herein, a novel defect-enriched Bi2Ti2O7/C3N4 (BTO/CN) heterojunction is prepared via ball milling-thermal treatment method and used as a durable photo-Fenton like catalyst to degrade phenol in water. The BTO/CN heterojunction shows an excellent optical absorption capacity, and a superior e--h+ separation efficiency. With the addition of PMS, a micro-photo-electrolysis reactor can be formed in the BTO/CN, rendering it high photocatalytic activity, excellent tolerance to environmental condition and exceptional stability. The BTO/CN micro-photo-electrolysis reactor exhibits superior performance in phenol removal and excellent tolerance towards salt ions. Non-radical pathway and OH oxidation are demonstrated to contribute to phenol degradation in the BTO/CN heterojunction photo-Fenton-like system. The PMS can simultaneously boost the interfacial charge transmission from BTO to CN forming internal BTO photoanode and CN photocathode, leading to sustainable photocatalytic performance without secondary pollution. This work successfully demonstrates a feasible strategy to develop solar energy assisted Fenton-like catalyst for efficient water decontamination, which holds a great promise towards practical photo-Fenton water decontamination.