A variety of water-treating anodes have been developed and studied over the past four decades, among which Sb-SnO2 should be the most practicable in terms of treatment efficiency, cost-competitiveness and environmental non-toxicity. There are several features of Sb-SnO2 anode and the most unique and outstanding is its high oxygen evolution potential and generation of hydroxyl radical. Our previous study compared Sb-SnO2 and RuO2 (coated on Ti foil) anodes under various experimental conditions and found that the former is generally superior to the latter in treating contaminated water yet its superior performance highly depends on the kind of employed electrolytes. Such electrolyte-dependent performance was also confirmed with multi-layered BiOx-TiO2 anodes which have faster kinetics in transforming contaminants in sodium chloride electrolyte but similar kinetics in combusting them into carbon dioxide in sodium sulfate when powered by photovoltaic arrays.