Tailored mesoporous nanocrystalline Ga2O3 for dye-selective photocatalytic degradation

Porous brick-like low dimensional Ga2O3 nanostructures were fabricated through a low-cost chemical route having different phases synthesized at different temperatures. The pore-density was varied by varying synthesis temperature and the materials exhibited a transformation from α-hexagonal to β-monoclinic phase. With traditional structural and morphological characterization, detailed contaminant removal properties were investigated for the as-prepared samples. The green cleaning efficiency was recognized to be influenced by crystal structure, surface morphology and surface charge type of the catalyst. All of the synthesized material showed promising performance in degradation of traditional organic hazardous dyes like rhodamine B (RhB), methyl orange (MO) and apparently invisible harmful water soluble chemical like phenol. An interesting feature, i.e., obtaining dye specific adsorbent out of the same materials and the mechanism for the ion selective photo-degradation process have been presented in this work. High degradation rate constants of 0.072 min−1, 0.051 min−1 and 0.18 min−1 were obtained for RhB, MO and mixed dyes respectively with almost complete removal of the dyes. The role of intermediate radicals •OH, •O2− and h+ was correlated with catalytic performances depending upon modification of band positions of the dyes. The mesoporous Ga2O3 structures are hence inferred as potential candidates for future water safety issues. [Display omitted] •Facile chemical synthesis with associated phase transition.•Tuning of pore density and pore diameter with calcination temperature.•Detail study of photocatalysis performance and proposed application as dye selective photocatalyst.•Application of the most efficient sample for phenol removal from water.•Technique applicable for similar oxide systems.