Synergy effect between tetracycline and Cr(VI) on combined pollution systems driving biochar-templated Fe3O4@SiO2/TiO2/g-C3N4 composites for enhanced removal of pollutants

Abstract

Biochar-coupled Fe3O4@SiO2/TiO2/g-C3N4 composites were successfully constructed through simple sol–gel and calcination methods. The composites efficiently removed high-concentration toxic tetracycline (TC) by means of ·OH and ·$${\rm O}_2^{-}$$ O 2 - , whose removal rate exhibited 91.88% during 3 h, and the degradation rate constant reached up to 0.0068 min−1. The excellent performance can be attributed to the high specific surface area, enhanced visible light response, the introduction of magnetic nanoparticles and biochars expediting charge transfer, Z-scheme heterojunction enhancing the spatial separation of photo-generate carriers and, importantly extraordinary adsorption capacity of 147.96 mg g−1. Moreover, the composites showed the most excellent efficiency under the calcination temperature of 450 ℃, and exhibited good stability with tolerance to a wide range of pH and anions. Interestingly, a synergistic photocatalytic effect was discovered in the TC/Cr(VI) combined pollution systems, resulting in significantly improved removal of Cr(VI). Besides, the photocatalytic mechanism and degradation path of tetracycline were also elucidated. All these findings suggested the as-synthesized catalyst was an excellent photocatalyst for removal of TC/Cr(VI)-contaminated water. Graphical Abstract

Catalyst-Enhancing Hydrothermal Carbonization of Biomass for Hydrochar and Liquid Fuel Production—A Review

“…Catalysts play a crucial role in either the thermal conversion process or ex situ upgrading via impacting the overall multiscale design of these processes [56,57]. To ensure the best catalyst combination and process design, the catalytic upgrading of HTC necessi-…”

“…Catalysts play a crucial role in either the thermal conversion process or ex situ upgrading via impacting the overall multiscale design of these processes [ 56 , 57 ]. To ensure the best catalyst combination and process design, the catalytic upgrading of HTC necessitates a thorough understanding of the chemical reactions that result in the desired products, as well as the identification of the catalyst species that would favor these transformations at various process configurations [ 57 , 58 ]. This is a complex challenge due to the three following reasons: (A) There are many components present in the product, derived from the sequential reactions happening during the biomass thermal conversion process.…”

Cross-polymerization between bio-oil and polyaniline: synergistic effects on pore development in subsequent activation and adsorption of phenol

“…3f shows the characterization results of FT-IR about the distribution of functional groups of the samples. The bio-oil contained a rich variety of organics, especially the oxygen-containing functional groups like -OH, 29 CO and C-O with the absorption at 3424, 1708 and 1024-1111 cm −1 , respectively. The high ratio of CO to CC in the bio-oil further confirmed the higher abundance of CO (Fig.…”

A Review on Effective Photocatalytic Remediation of Noxious Pollutants Utilizing Biochar Tailored Graphitic Carbon Nitride

“…Other than that, BC also reduces environmental risks by serving as a alternative to the semiconductor part of photocatalysts. 113 Wang et al synthesized carbon spheres derived from bamboo biochar via a two-step hydrothermal process and then modified them with g-C 3 N 4 to form BS@g-C 3 N 4 . The protonated g-C 3 N 4 sheets in this catalyst serve as the primary photocatalysts, while the biochar sphere functions as both a reservoir and a sensitizer.…”