Presence of arsenic (As) in water is both toxic and carcinogenic and is one of the most widespread problems around the globe. Metal oxides with specific affinities and high surface areas have proved to be promising adsorbents as well as photocatalysts towards arsenic removal from water. Presence of high affinity surface hydroxyl groups coupled with enormous surface area and porous surface morphology have resulted in exceptional high arsenic removal capacities from water. Arsenic removal is accompanied by the mechanisms of surface migration, deprotonation, oxidation, redox reactions, ligand exchange or charge complexations. This review critically analyses the synthesis, application of various heterostructures of metal oxide, possible mechanism towards arsenic removal from water and its usefulness over conventional adsorbents. Future scopes and challenges for robust and economical solutions towards arsenic free water have also been explored.

水中的砷 (As) 既有毒又致癌，是全球最普遍的问题之一。具有特定亲和力和高表面积的金属氧化物已被证明是有前途的吸附剂和光催化剂，用于从水中去除砷。高亲和力表面羟基的存在加上巨大的表面积和多孔表面形态，导致从水中去除砷的能力非常高。砷去除伴随着表面迁移、去质子化、氧化、氧化还原反应、配体交换或电荷络合的机制。这篇综述批判性地分析了金属氧化物各种异质结构的合成、应用、从水中去除砷的可能机制及其对传统吸附剂的有用性。