Fe-doped cryptomelane synthesized by refluxing at atmosphere: Structure, properties and photocatalytic degradation of phenol.
Fe-doped cryptomelanes were synthesized by refluxing at ambient pressure, followed by characterization with multiple techniques and test in photocatalytic degradation of phenol. The introduction of Fe(III) into the structure of cryptomelane results in a decrease in particle size and the contents of Mn and K(+), and an increase in the Mn average oxidation state (AOS), specific surface area and UV-vis light absorption ability. Mn and Fe K-edge extended X-ray absorption fine structure spectroscopy analysis indicates that some Fe(III) is incorporated into the framework of cryptomelane by replacing Mn(III) while the remaining Fe(3+) is adsorbed in the tunnel cavity. These Fe-doped cryptomelanes have significantly improved the photocatalytic degradation rate of phenol, with the sample of ∼3.04 wt.% Fe doping being the most reactive and achieving a degradation rate of 36% higher than that of the un-doped one. The enhanced reactivity can be ascribed to the increase in the coherent scattering domain size of the crystals, Mn AOS and light absorption, as well as the presence of sufficient K(+) in the tunnel. The results imply that metal doping is an effective way to improve the performance of cryptomelane in pollutants removal and has the potential for modification of Mn oxide materials.
Key Laboratory of Arable Land Conservation (Middle and Lower Reaches of Yangtze River), Ministry of Agriculture, College of Resources and Environment, Huazhong Agricultural University, Wuhan 430070, China.
Hui
H
Yin
Key Laboratory of Arable Land Conservation (Middle and Lower Reaches of Yangtze River), Ministry of Agriculture, College of Resources and Environment, Huazhong Agricultural University, Wuhan 430070, China.
Xiaoxue
X
Dai
Department of Ecosystem Science and Management, University of Wyoming, Laramie, WY 82071, USA.
Mengqiang
M
Zhu
School of Environmental Science and Engineering, Nanjing University of Information Science & Technology, Nanjing 210044, China.
Feihu
F
Li
Key Laboratory of Arable Land Conservation (Middle and Lower Reaches of Yangtze River), Ministry of Agriculture, College of Resources and Environment, Huazhong Agricultural University, Wuhan 430070, China.
Xionghan
X
Feng
Key Laboratory of Arable Land Conservation (Middle and Lower Reaches of Yangtze River), Ministry of Agriculture, College of Resources and Environment, Huazhong Agricultural University, Wuhan 430070, China. Electronic address: liufan@mail.hzau.edu.cn.
Fan
F
Liu
D002384:Catalysis; D005290:Ferric Compounds / Q000737:chemistry*; D008027:Light; D017895:Manganese Compounds / Q000138:chemical synthesis* / Q000737:chemistry; D008855:Microscopy, Electron, Scanning; D010087:Oxides / Q000138:chemical synthesis* / Q000737:chemistry; D010316:Particle Size; D019800:Phenol / Q000737:chemistry* / Q000528:radiation effects; D056951:Photoelectron Spectroscopy; D010782:Photolysis; D013499:Surface Properties; D014961:X-Ray Diffraction
D005290:Ferric Compounds; D017895:Manganese Compounds; D010087:Oxides; D019800:Phenol; C027424:manganese oxide
Cryptomelane; Fe doping; Photocatalytic degradation; Powder X-ray diffraction; XAFS