Kanagaraj Thamaraiselvi, Murphin Kumar Paskalis Sahaya, Thomas Reshma, Kulandaivelu Ravichandran, Subramani Rajeswari, Mohamed Roshan Noor, Lee Sijin, Chang S Woong, Chung W Jin, Nguyen D Duc
Department of Analytical Chemistry, University of Madras, Chennai, Tamilnadu, India.
Department of Civil and Environmental Engineering, Yonsei University, Seoul, 03722, Republic of Korea.
Environ Res. 2022 Apr 1;205:112439. doi: 10.1016/j.envres.2021.112439. Epub 2021 Nov 29.
Combining the pure α- and β-phases of bismuth oxide enhances its photocatalytic activity under both visible and solar irradiation. α-BiO, β-BiO and α/β-BiO were synthesized by a solvothermal calcination method. The structural, optical, and morphological properties of the as-synthesized catalysts were analyzed using XRD, UV-DRS, XPS, SEM, TEM, and PL. The bandgaps of α/β-BiO, α-BiO, and β-BiO were calculated to be 2.59, 2.73, and 2.34 eV, respectively. The photocatalytic activities of the catalysts under visible and solar irradiation were examined by the degradation of carcinogenic reactive blue 198 and reactive black 5 dyes. The kinetic plots of the degradation reactions followed pseudo-first-order kinetics. α/β-BiO exhibited higher photocatalytic activity (∼99%) than α-BiO and β-BiO under visible and solar irradiation. The TOC and COD results confirmed the maximum degradation ability of α/β-BiO, and the decolorization percentage remained above 90%, even after five cycles under visible irradiation. The photocatalytic dye degradation mechanism employed by α/β-BiO was proposed based on active species trapping experiments.
结合氧化铋的纯α相和β相可提高其在可见光和太阳光照射下的光催化活性。采用溶剂热煅烧法合成了α-BiO、β-BiO和α/β-BiO。利用XRD、UV-DRS、XPS、SEM、TEM和PL对合成的催化剂的结构、光学和形态性质进行了分析。计算得出α/β-BiO、α-BiO和β-BiO的带隙分别为2.59、2.73和2.34 eV。通过降解致癌活性蓝198和活性黑5染料，考察了催化剂在可见光和太阳光照射下的光催化活性。降解反应的动力学曲线符合准一级动力学。在可见光和太阳光照射下，α/β-BiO表现出比α-BiO和β-BiO更高的光催化活性（约99%）。TOC和COD结果证实了α/β-BiO的最大降解能力，即使在可见光照射下经过五个循环，脱色率仍保持在90%以上。基于活性物种捕获实验，提出了α/β-BiO的光催化染料降解机理。
