Athar Muhammad, Fiaz Muhammad, Farid Muhammad Asim, Tahir Muhammad, Asghar Muhammad Adnan, Ul Hassan Sadaf, Hasan Murtaza
Institute of Chemical Sciences, Bahauddin Zakariya University, Multan 60800, Pakistan.
Department of Chemistry, Division of Science and Technology, University of Education, Lahore, Pakistan.
ACS Omega. 2021 Mar 10;6(11):7334-7341. doi: 10.1021/acsomega.0c05412. eCollection 2021 Mar 23.
Photoelectrocatalysts are robust materials for the production of energy through different ways such as water splitting. Narrow optical band gaps and high overpotentials are limiting the development of photoelectrocatalysts. In this study, a series of CoFe Mn WO solid solutions of cobalt tungstate codoped with iron and manganese have been synthesized hydrothermally. The synthesized solid solutions have been characterized by powder XRD, UV-visible spectra, cyclic voltammetry (CV), and linear sweep voltammetry (LSV). They all crystallize in a wolframite-type monoclinic crystal system with space group 2/. Doping of iron and manganese leads to narrowing of the optical band gap of CoFe Mn WO from 2.60 to 2.04 eV. The electrocatalytic activity toward oxygen evolution reaction of all of the samples has been evaluated through LSV measurements. It is found that the sample named C5, which is codoped with manganese and iron, has the lowest onset potential and needs the lowest overpotential to attain the targeted 5 mA cm and standard 10 mA cm current densities as compared with all other synthesized samples. This study shows that the synthesized tungstates can be good candidates for the photoelectrocatalytic oxygen evolution reaction.
光电催化剂是通过诸如水分解等不同方式生产能源的坚固材料。窄光学带隙和高过电位限制了光电催化剂的发展。在本研究中，通过水热法合成了一系列铁和锰共掺杂的钨酸钴CoFeMnWO固溶体。通过粉末XRD、紫外可见光谱、循环伏安法（CV）和线性扫描伏安法（LSV）对合成的固溶体进行了表征。它们均结晶为空间群为2/的钨锰矿型单斜晶体系统。铁和锰的掺杂导致CoFeMnWO的光学带隙从2.60 eV缩小到2.04 eV。通过LSV测量评估了所有样品对析氧反应的电催化活性。结果发现，与所有其他合成样品相比，锰和铁共掺杂的样品C5具有最低的起始电位，并且达到目标5 mA cm和标准10 mA cm电流密度所需的过电位最低。本研究表明，合成的钨酸盐可成为光电催化析氧反应的良好候选材料。
