Dielectric Barrier Discharge Fe doping History of engineering & technology MIL-53(Fe) Ni/Fe-MOF Z-scheme adsorption anatase/brookite biphasic cobalt oxide(II,III) copper(II) oxide degradation of dyes dye photodecomposition graphitic carbon nitride hydrothermal reaction indigo carmine nitrogen-doping phosphorescence photocatalytic decomposition of rhodamine B photocatalytic fuel cell polyaniline regeneration resin sol-gel method strontium aluminates titanium dioxide visible light irradiation visible light photocatalysis