The present paper reports the development of TiO₂ photocatalysts adsorbed with squaraine dyes for the utilization of visible light. We synthesized 1,3-bis(3,3-dimethyl-2-methylene indolenine)squaraine (ISQ) and its derivatives having two COOH (ISQ-(COOH)₂), COOH and COOC₄H₉ (ISQ-COOHCOOBu) and two COOC₄H₉ groups (ISQ-(COOBu)₂) at both ends. We used porous TiO₂ which was synthesized by a sol–gel method and possessed a specific surface area of 229 m² g⁻¹. ISQ without an anchoring group of COOH hardly adsorbed and the number of the adsorbed ISQ-(COOH)₂ or ISQ-COOHCOOBu per gram of TiO₂ was estimated to be (5.53 ± 0.74) × 10^-5 or (5.93 ± 0.68) × 10^-5 mol g⁻¹, respectively. Photocatalytic degradation of methyl orange (MO) was performed on TiO₂ adsorbed with ISQ-(COOH)₂ or ISQ-COOHCOOBu in the range of (0.12–5.4) × 10^-5 or (0.15–6.2) × 10^-5 mol g⁻¹. The degradation rate increased drastically with an increase in the adsorbed amounts of these dyes less than 1.7 × 10^-5 mol g⁻¹ but then increased gradually up to ca. 6 × 10^-5 mol g⁻¹. The electrochemical measurements revealed that the photogenerated electron was transferred from these dyes to the conduction band of TiO₂. No MO was degraded on TiO₂ adsorbed with ISQ-(COOH)₂ in the nitrogen atmosphere under VL irradiation. We proposed the degradation mechanism of MO on TiO₂ adsorbed with ISQ-(COOH)₂ or ISQ-COOHCOOBu.

本论文报道了用方酸染料吸附的 TiO ₂光催化剂用于可见光的开发。我们合成了 1,3-双 (3,3-二甲基-2-亚甲基吲哚啉) 方酸 (ISQ) 及其具有两个 COOH (ISQ-(COOH) ₂ )、COOH 和 COOC ₄ H ₉ (ISQ-COOHCOOBu) 的衍生物和两端有两个COOC ₄ H ₉基团(ISQ-(COOBu) ₂ )。我们使用通过溶胶-凝胶法合成的多孔TiO ₂，其比表面积为229 m ² g ^-1。不含COOH锚定基团的ISQ几乎不吸附，吸附ISQ-(COOH) _2的数量或ISQ-COOHCOOBu/g TiO ₂估计分别为（5.53±0.74）×10 ^-5或（5.93±0.68）×10 ^-5 mol g ^-1。在 (0.12–5.4) × 10 ^-5或 (0.15–6.2) × 10 ^-5 mol g范围内吸附有 ISQ-(COOH) ₂或 ISQ-COOHCOOBu 的TiO ₂上进行甲基橙 (MO) 的光催化降解^-1。随着这些染料吸附量的增加小于 1.7 × 10 ^-5 mol g ^-1，降解率急剧增加，但随后逐渐增加到大约。6 × 10 ^-5摩尔克^-1. 电化学测量表明光生电子从这些染料转移到 TiO ₂的导带。在 VL 照射下，在氮气氛中吸附有 ISQ-(COOH) _{2 的}TiO ₂上没有 MO 降解。我们提出了MO在用ISQ-(COOH) ₂或ISQ-COOHCOOBu吸附的TiO ₂上的降解机制。