TiO₂ is an attractive semiconductor suitable for photocathodic protection, but its weak absorption of visible light and low quantum yield limit its usage. Here, a new heterostructured SnIn₄S₈ nanosheet/TiO₂ nanotube photoanode was prepared and its photocathodic protection performance was analyzed. SnIn₄S₈ nanosheets were uniformly deposited on the surface of the TiO₂ nanotube via a solvothermal treatment. The SnIn₄S₈/TiO₂ composite exhibited better photocathodic protection performance compared with pure TiO₂ nanotubes, owing to its good visible-light response and photogenerated carrier separation efficiency. Moreover, the composite exhibited a maximum photocurrent density of 100 μA cm⁻² for a 6 h solvothermal reaction under visible light irradiation. The negative shift of the photoinduced potential of Q235 carbon steel connected to the composite could reach 0.45 V versus SCE. Therefore, the SnIn₄S₈/TiO₂ composite can offer efficient photocathodic protection for Q235 carbon steel against corrosion in 3.5 wt% NaCl solution. This work provides a new approach for the development of high-efficient photoanode materials for the photocathodic protection of metals.

TiO ₂是适用于光阴极保护的有吸引力的半导体，但是其对可见光的吸收弱和量子产率低限制了其用途。在此，制备了一种新型的异质结构SnIn ₄ S ₈纳米片/ TiO ₂纳米管光阳极，并对其光阴极保护性能进行了分析。通过溶剂热处理将SnIn ₄ S ₈纳米片均匀地沉积在TiO ₂纳米管的表面上。与纯TiO ₂相比，SnIn ₄ S ₈ / TiO ₂复合材料具有更好的光阴极保护性能。纳米管，由于其良好的可见光响应和光生载流子分离效率。此外，对于可见光照射下的6小时溶剂热反应，该复合物表现出最大光电流密度为100μAcm ^-2。与SCE相比，连接到复合材料的Q235碳钢的光感应电势的负移可能达到0.45V。因此，SnIn ₄ S ₈ / TiO ₂复合材料可以为Q235碳钢提供有效的光阴极保护，使其免受3.5 wt％NaCl溶液的腐蚀。这项工作为开发用于金属光阴极保护的高效光阳极材料提供了一种新方法。