Jamil Sadaf, Jabeen Naila, Sajid Fatima, Khan Latif U, Kanwal Afia, Sohail Manzar, Zaheer Muhammad, Akhter Zareen
Department of Chemistry, Quaid-i-Azam University Islamabad 45320 Pakistan.
Nanosciences and Technology Division, National Centre for Physics QAU Campus, Shahdra Valley Road, P.O. Box 2141 Islamabad-44000 Pakistan
RSC Adv. 2024 Aug 1;14(33):24092-24104. doi: 10.1039/d4ra03402c. eCollection 2024 Jul 26.
This work presents a comparative study on the structural, optical and electrochemical characteristics of visible light driven (VLD) reduced titanium dioxide (TiO ) nanocatalysts synthesized inorganic and organic synthetic routes. X-ray diffraction (XRD) patterns, Raman spectra and X-ray absorption fine structure (XAFS) analyses reflected anatase phase titania. Whereas, the quantitative EXAFS fit and XANES analysis revealed structural distortion due to the presence of oxygen and titanium vacancies with low valent Ti states in anatase lattices of certain nanocatalysts, which subsequently leads to better electrochemical and photocatalytic activities. Moreover, owing to the large surface area and mesoporous structures, the Mg-TiO nanocatalysts exhibited enhanced water adsorption and ultimately increased overall water splitting with an OER overpotential equal to 420 mV RHE at a current density of 10 mA cm (Tafel slope = 62 mV dec), extended visible light absorbance, decreased photoluminescence (PL) intensity and increased carrier lifetime in comparison with commercial titania.
这项工作对通过无机和有机合成路线合成的可见光驱动（VLD）还原二氧化钛（TiO₂）纳米催化剂的结构、光学和电化学特性进行了比较研究。X射线衍射（XRD）图谱、拉曼光谱和X射线吸收精细结构（XAFS）分析表明为锐钛矿相二氧化钛。然而，定量EXAFS拟合和XANES分析显示，某些纳米催化剂的锐钛矿晶格中由于存在氧和低价钛态的钛空位而导致结构畸变，这随后导致更好的电化学和光催化活性。此外，由于大表面积和介孔结构，Mg-TiO₂纳米催化剂表现出增强的水吸附，最终在电流密度为10 mA cm⁻²（塔菲尔斜率 = 62 mV dec⁻¹）时使总体水分解增加，其析氧反应（OER）过电位等于420 mV（相对于可逆氢电极，RHE），与商业二氧化钛相比，具有扩展的可见光吸收、降低的光致发光（PL）强度和增加的载流子寿命。
