Electrochemically regenerative visible light-induced reactivity of α-Fe2O3 films with Ag(core)–AgCl(shell) microcrystal composites

Ag(core)–AgCl(shell) microcrystal composites (Ag@AgCl) have been formed on an α-Fe2O3 film-coated SnO2 electrode by a 2 step method consisting of the electrochemical reduction of Ag+ ions and the subsequent electrochemical oxidation. The synergy of α-Fe2O3 and Ag@AgCl gave rise to a high visible light-induced reactivity (λex > 420 nm) for the oxidation of 2-naphthol (2-NAP) used as a model water pollutant in the presence and absence of oxygen. These findings were attributable to the function of Ag@AgCl composites as an excellent charge-separation promoter and built-in acceptor.