This work reports a key factor, the H₂SO₄ concentration, in controlling the physicochemical properties of titanium dioxide (TiO₂) photocatalysts during the sol–gel synthesis. The photocatalysts synthesized using different concentrations of H₂SO₄ possess specific anatase/rutile ratios and crystallite sizes as well as surface areas, resulting in different photocatalytic performance in the degradation of formic acid in solution. The best photocatalytic performance is observed for the TiO₂ photocatalyst containing a relatively high percentage of the rutile phase (∼84%), which is obtained from the sol–gel synthesis without H₂SO₄.

中文翻译：

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溶胶-凝胶法TiO2的带隙优化及其对甲酸光降解的影响

这项工作报告了一个关键因素，即 H ₂ SO ₄浓度，它在溶胶-凝胶合成过程中控制二氧化钛 (TiO ₂ ) 光催化剂的物理化学性质。使用不同浓度的H ₂ SO ₄合成的光催化剂具有特定的锐钛矿/金红石比例和微晶尺寸以及表面积，导致溶液中甲酸降解的光催化性能不同。对于含有相对高百分比金红石相 (~84%)的 TiO ₂光催化剂，观察到最好的光催化性能，该相是从溶胶-凝胶合成中获得的，没有 H ₂ SO ₄。