Almazroai Layla, El-Mekawy Rasha E, Musa Rihab, Ali Lina
Department of Chemistry, Faculty of Applied Science, Umm Al-Qura University Makkah Saudi Arabia
Department of Petrochemicals, Egyptian Petroleum Research Institute Nasr City Cairo Egypt.
RSC Adv. 2022 May 31;12(25):15992-16002. doi: 10.1039/d2ra00788f. eCollection 2022 May 23.
Sensitization of TiO by dyes such as cyanine and their derivatives is used as a technique to improve potency for the production of hydrogen gas as an alternative green fuel. These dyes shift the spectrum of TiO from the UV region to the visible region, enabling it to harvest as much sunlight as possible. Herein, four different derivatives of cyanine (labelled C1, C2, C3, and C4) were prepared and doped in Ag/TiO the impregnation method. The properties of the prepared photocatalysts were studied by XRD, SEM-EDS, FTIR, and UV-visible spectroscopy. The sensitized photocatalysts exhibited a similar morphology, nanoscale particle size, and good absorbance in the visible region. The rate constant for the photocatalytic activity of Ag/TiO showed a great enhancement for hydrogen evolution after sensitization from 0.088 to 0.33 μmol min. Doping of the C2 derivative in Ag/TiO promoted the photocatalytic and sonophotocatalytic rates of H production by 7.5 and 9 times, respectively. Also, the amount of photocatalyst had a significant effect on the photocatalytic activity of the sensitized Ag/TiO, where 0.14 g was the optimum dose, giving the maximum yield at both the initial rate and 300 min. One of the important factors causing the efficiency to reach high levels is the inhibition of photogenerated electron/hole recombination. This was achieved by adding a small quantity of methanol, which increased the rate by 9 times. The stability of the prepared photocatalysts was tested, which gave good results even after their 5th use. All the results confirmed that the sensitization of metal oxides is a promising solution in industry to produce clean energy (H) in high quantities over highly stable photocatalysts.
通过诸如花青及其衍生物等染料对二氧化钛进行敏化，被用作一种提高氢气生产效率的技术，氢气是一种替代绿色燃料。这些染料将二氧化钛的光谱从紫外区域转移到可见区域，使其能够尽可能多地收集阳光。在此，制备了四种不同的花青衍生物（标记为C1、C2、C3和C4），并通过浸渍法将其掺杂到Ag/TiO₂中。通过X射线衍射（XRD）、扫描电子显微镜-能谱仪（SEM-EDS）、傅里叶变换红外光谱（FTIR）和紫外-可见光谱对制备的光催化剂的性能进行了研究。敏化后的光催化剂呈现出相似的形态、纳米级粒径以及在可见光区域良好的吸光度。Ag/TiO₂光催化活性的速率常数在敏化后析氢方面有显著提高，从0.088 μmol/min提升至0.33 μmol/min。在Ag/TiO₂中掺杂C2衍生物分别使光催化和超声光催化产氢速率提高了7.5倍和9倍。此外，光催化剂的用量对敏化后的Ag/TiO₂的光催化活性有显著影响，其中0.14 g是最佳剂量，在初始速率和300 min时均能产生最大产率。导致效率达到高水平的一个重要因素是抑制光生电子/空穴复合。这通过添加少量甲醇得以实现，甲醇使速率提高了9倍。对制备的光催化剂的稳定性进行了测试，即使在第五次使用后仍得到了良好的结果。所有结果证实，金属氧化物的敏化是工业上通过高度稳定的光催化剂大量生产清洁能源（氢气）的一种有前景的解决方案。
