A simple preparation method of in situ oxidized titanium carbide MXene for photocatalytic degradation of catechol

Abstract

Photocatalytic systems have been widely applied to treat the highly toxic and refractory aromatic sewage water pollution problem. However, the development of highly active and excellent durability photocatalysts has always been the long-term challenge for water pollution control. In this work, a kind of MXene (MX) Ti₃C₂–TiO₂ composite has been successfully fabricated by in situ oxidation using a simple method. The removal efficiencies of MX-TiO₂(200) for catechol (CC) were up to 92% under simulated sunlight radiation for 90 min, with a rate constant k of 0.0243 min⁻¹. Compared with pristine MX Ti₃C₂, such a Ti₃C₂–TiO₂ composite remarkably accelerated the formation rates of ˙O₂⁻ and ˙OH due to its metallic nature and large specific surface area, which further accelerates the migration of photogenerated carriers (generated by TiO₂) to Ti₃C₂. The activity of the MX-TiO₂(200) did not show noticeable variation after 5-times recycling. A possible Schottky barrier electron transfer mechanism for MX-TiO₂ composite degradation of catechol pollutants was further proposed. The MX-TiO₂(200) composite developed in this study exhibits great potential as an ideal photocatalyst for application in phenolic pollutant wastewater treatment.