Dutta Dimple P, Dagar Divya
Chemistry Division, Bhabha Atomic Research Centre, Mumbai 400085, India.
Department of Applied Chemistry, Amity University, Gurgaon, Haryana 122413, India.
J Nanosci Nanotechnol. 2020 Apr 1;20(4):2179-2194. doi: 10.1166/jnn.2020.17333.
This study reports the synthesis, characterization and water remediation application of novel AlVO₄/g-C₃N₄ nanocomposites. The nanocomposite has been synthesized by a low temperature solid-state reaction using graphitic carbon nitride (g-C₃N₄) obtained via calcination of melamine and AlVO₄ prepared via assisted sonochemical technique. Powder X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), Fourier Transform Infrared spectroscopy (FTIR), ultraviolet-visible diffuse reflection spectroscopy (UV-vis DRS), and the N₂ gas adsorption Brunauer-Emmett-Teller (BET) method has been used to characterize the pristine and composite samples. AlVO₄ and g-C₃N₄ interact with each other forming a hybrid composite, which shows excellent ability for selective sorption of cationic MB (methylene blue) dye from wastewater. The initial dye concentration, pH and amount of sorbent has been varied and their effect on the adsorption process has been analysed. The photocatalytic efficiency of the MB dye adsorbed pristine g-C₃N₄, AlVO₄:g-C₃N₄ (1:3) and AlVO₄:g-C₃N₄ (1:1) composite has been tested under visible light. With increased proportion of AlVO₄ in the samples, the photocatalytic efficiency improved and the best photodegradation has been observed for the AlVO₄:g-C₃N₄ (1:1) sample. Photoluminescence (PL) studies, photocurrent response measurements and electrochemical impedance spectroscopy (EIS) indicates enhanced separation of the photogenerated electron/hole pairs leading to effective degradation of the MB dye solution in case of the AlVO₄:g-C₃N₄ (1:1) composite sample. The photocatalytic mechanism has been elucidated and it could be inferred that photogenerated holes and superoxide anion radicals play a major role in the photocatalysis process.
本研究报道了新型AlVO₄/g-C₃N₄纳米复合材料的合成、表征及水修复应用。该纳米复合材料通过低温固相反应合成，使用经三聚氰胺煅烧得到的石墨相氮化碳（g-C₃N₄）和通过辅助声化学技术制备的AlVO₄。采用粉末X射线衍射（XRD）、扫描电子显微镜（SEM）、透射电子显微镜（TEM）、傅里叶变换红外光谱（FTIR）、紫外-可见漫反射光谱（UV-vis DRS）以及N₂气体吸附的布鲁诺尔-埃米特-特勒（BET）方法对原始样品和复合样品进行表征。AlVO₄和g-C₃N₄相互作用形成杂化复合材料，该复合材料对废水中阳离子亚甲基蓝（MB）染料具有优异的选择性吸附能力。改变了初始染料浓度、pH值和吸附剂用量，并分析了它们对吸附过程的影响。在可见光下测试了吸附MB染料的原始g-C₃N₄、AlVO₄:g-C₃N₄（1:3）和AlVO₄:g-C₃N₄（1:1）复合材料的光催化效率。随着样品中AlVO₄比例的增加，光催化效率提高，并且在AlVO₄:g-C₃N₄（1:1）样品中观察到最佳的光降解效果。光致发光（PL）研究、光电流响应测量和电化学阻抗谱（EIS）表明，在AlVO₄:g-C₃N₄（1:1）复合样品中，光生电子/空穴对的分离增强，导致MB染料溶液有效降解。阐明了光催化机理，可以推断光生空穴和超氧阴离子自由基在光催化过程中起主要作用。
