Journal of Materials Science, Vol.53, No.16, 11694-11714, 2018
Influence of cation doping (Li+, Na+, K+) on photocatalytic activity of MIL-53(Fe)
The work highlights the influence of cation doping on photocatalytic activity of MIL-53(Fe) in artificial light. The effect of intrinsic factors, viz. band-gap energy, electron conductivity and surface area, influencing photocatalysis was studied in detail w.r.t. the degradation of brilliant green dye both in the presence and in the absence of H2O2 as an electron scavenger. Reduction in band gap after cation doping was observed for Li+ (1.81 eV), Na+ (1.875 eV) and K+ (1.89 eV) when compared with the parent MIL-53(Fe) (1.95 eV). However, the photoactivity of the synthesized materials was in the following progression: MIL-53(Fe)(81.6%) > Li-MIL-53(Fe)(27.6%) > Na-MIL-53(Fe)(25.77%) > K-MIL-53(Fe) (24.18%). Effect of structural distortions in the octahedral backbone of MIL-53(Fe) due to cation doping was inferred as the plausible reason behind such behavior. The degree of electron delocalization and specific surface areas were found to be in the following progression: Na-MIL-53(Fe) (very low, 7.72 m(2) g(-1)) < K-MIL-53(Fe) (low, 28.38 m(2) g(-1)) < Li-MIL-53(Fe) (moderate, 42.14 m(2) g(-1)) < MIL-53(Fe) (high, 51.71 m(2) g(-1)), indicating that the intrinsic material properties have combinatorial influence on photocatalytic activity.