O2 activation and 1O2 generation over phosphate modified BiOCl for efficient photodegradation of organic pollutants

Abstract

Phosphate modification over semiconductor photocatalyst was an effective route to promote photodegradation of organic pollutants. Studies on promoted O2 adsorption, better charge separation, and free ∙OH radicals raised from phosphate modification are clear, whereas O2 activation and the generated reactive oxygen species (·O2-, H2O2, and 1O2) have been ignored. Herein, the hydrogen bond network constructed between BiOCl surface and phosphate weaken the surface Bi-O bond thus benefit the formation of oxygen vacancy (OVs). OVs not only facilitate the adsorption of organic pollutants but also promote the O2 activation to generate H2O2 and 1O2. Another route for 1O2 generation relies on the H2O2 reacted with HClO from lattice chlorine oxidation was demonstrated. The directly attack of surface adsorbed 4-CP via h+, in addition with the selective oxidation via 1O2, synergetically contribute excellent photodegradation performance. This study systematically reveals the O2 activation and 1O2 generation for efficient photodegradation over phosphate modified BiOCl.