Solar photoelectrocatalytic degradation of Acid Orange 7 azo dye using a highly stable TiO2 photoanode synthesized by atmospheric plasma spray

► Synthesis of a TiO2 photoanode on stainless steel substrate by atmospheric plasma spray. ► Degradation of Acid Orange 7 by solar photoelectrocatalysis with a TiO2/air-diffusion cell. ► 15 mg L−1 azo dye, pH 7.0 and anodic current density of 1.0 mA cm−2 as best operating variables. ► Fast azo dye removal and total solution decolorization, but poor mineralization achieved. ► Phthalic, tartaric, succinic, acetic and oxalic acids as main by-products at long-electrolysis time.