Nitrogen-Doped TiO₂/Nitrogen-Containing Biochar Composite Catalyst as a Photocatalytic Material for the Decontamination of Aqueous Organic Pollutants

Abstract

In this study, a waste walnut shell-derived biochar enriched with nitrogen (N-biochar) is mixed with nitrogen-doped TiO 2 (N-TiO 2 ) to fulfill an affordable composite material for the degradation of methyl orange (MO). Results showed that porous structure and oxygen-containing functional groups of biochar facilitate contact with MO during the reaction process. Meanwhile, doped nitrogen has a positive effect on improving the reaction activity due to the existence of a substituted state and a gap state in the catalyst. It was revealed that the N-TiO 2 /N-biochar (NCNT0.2/1) exhibited better photocatalytic degradation efficiency (97.6%) and mineralization rate (85.4%) of MO than that of TiO 2 , N-TiO 2 , and TiO 2 /N-biochar due to its stronger synergistic effect of N, TiO 2 , and biochar, in accordance with its high charge separation by photoluminescence (PL) analysis. Trapping experiments showed that •OH is the predominant active species during the decolorization and mineralization process of MO. After five repeated use, the loss of activity of the catalyst was negligible. In addition, the catalytic degradation process was consistent with the pseudo-first-order kinetic model with the rate constant of 4.02 × 10 −2 min −1 .

A Facile Strategy for the Preparation of N-Doped TiO2 with Oxygen Vacancy via the Annealing Treatment with Urea

“…Table S1: BET surface area of P25, A-P25, N-P25 (2:1), N-P25 (1:1), and N-P25 (1:2). Table S2: Comparison of photocatalytic activity of N-TiO 2 photocatalyst for degradation of MO [43][44][45][46][47][48][49]. Data Availability Statement: Data will be made available on request.…”

SnS2 decorated biochar: a robust platform for the photocatalytic degradation and electrochemical sensing of pollutants

“…21–23 For example, Zuhong X et al prepared a highly porous N-TiO 2 /N-biochar composite for efficient removal of methylene orange dye from the aqueous medium. 24 The material exhibits photocatalytic degradation of methyl orange (97.6%) under visible light irradiation. In another study, Tahir Fazal et al integrated TiO 2 with biochar for the photodegradation of the methylene blue dye present in textile wastewater.…”

Waste Biomass-Mediated Synthesis of TiO2/P, K-Containing Grapefruit Peel Biochar Composites with Enhanced Photocatalytic Activity

“…Thuan et al [22] prepared a TiO 2 /rice husk biochar (TiO 2 /BC) composite that achieves a 97.6% removal rate for bisphenol A within 1 h under ultraviolet (UV) light. Xiong et al [23] prepared a N-TiO 2 /N-biochar composite using walnut husk biochar. Under mercury lamp irradiation, the photocatalytic degradation rate of methyl orange reached 97.6% within 100 min, with a mineralization rate of 85.4%.…”