Enhanced photocatalytic activity of porous TiO₂ containing C/P/K derived from grapefruit peel

Grapefruit peel possesses a porous structure and a significant specific surface area. In this study, we introduce an innovative and eco-friendly approach for synthesizing porous TiO₂. This was accomplished by employing grapefruit peel as a bio-template and tetrabutyl titanate as the precursor, utilizing a two-step rotary impregnation-calcination process. The TiO₂ faithfully reproduced the structural characteristics of the grapefruit peel across different scales, simultaneously incorporating C, P, K elements from the original grapefruit peel into the final samples. The fabricated samples were analyzed using XRD, XPS, SEM, TEM, BET, and UV-vis DRS. The results showed that the TiO₂ displays an anatase phase, and possesses a high specific surface area. The investigation of photocatalytic performance demonstrated that the CPK-TiO₂-10 sample exhibited outstanding photocatalytic activity against Rhodamine B (RhB) solution, achieving complete degradation within 60 minutes. Additionally, the total organic carbon (TOC) removal rate reached 91.34% after 60 minutes of irradiation. The sample maintained a high degradation efficiency, even after five recycling cycles. This exceptional performance can be attributed to its porous structure, enriched with pores and a larger surface area, as well as the beneficial effects of doping with C, P, K elements in TiO₂.