Novel green synthesis of TiO2 photocatalyst using matcha japanese green tea extract by sol-gel method: Influence of surface morphology on photocatalytic performance

A heterogenous photocatalyst such as commercial TiO2 (Degussa, P-25) is successfully applied under artificial UV irradiation for oxidation of organic pollutants. However, it suffers from limited surface area, thus affecting its photocatalytic performance and restricting its feasibility for industrial applications. The current study aimed to address this limitation and therefore it investigated, for the first time, matcha Japanese green tea (MJGT) as novel extracted material to greenly synthesized TiO2 photocatalyst from three weighted powders of first harvest (GF1, GF2, GF3) and second harvest (GS1, GS2, GS3) using sol-gel method (effective method in controlling surface morphology). To achieve this aim, a working protocol was adopted in three stages including chemical and green synthesis of TiO2, characterization of synthesized photocatalysts using relevant analytical techniques, and evaluation of their photocatalytic performance with methylene blue using batch photoreactor. Experimentally, surface morphology of greenly TiO2 photocatalysts in terms of crystallite sizes, mean particle size, surface roughness, BET surface area (SBET) and optical properties as found by analyses of EDX, FE-SEM, AFM, BET, and UV-vis, respectively, was significantly enhanced compared with chemically control TiO2 (CP). The best characterization results of greenly TiO2 photocatalysts were at GF2 and GS2. In particular, the SBET results were 164.44 m2/g for GF2 and 217.66 m2/g for GS2 compared with 13.78 m2/g for CP. Photocatalytic degradation of MB was 90% for GF2 and 98% for GS2. Photocatalytic mineralization of MB was 88% for GF2 and 97% for GS2. In conclusion, significantly, MJGT modified surface morphology of TiO2 towards enhancing its photocatalytic performance.