Chao Yao

Volatile organic compounds (VOCs) pose risks to human health and the environment, making the development of efficient technologies to reduce their emissions a priority. Catalytic oxidation represents a simple, efficient and environmentally friendly method for eliminating VOCs. Herein, a spinel CuCo ₂ O ₄ /biochar/attapulgite (ATP) composite was successfully synthesized via a sol–gel method using waste walnut shell powder as both a complexing agent and a combustion promoter. The effect of the mass ratio on toluene degradation performance was systematically investigated. The results indicated that when the mass ratio of CuCo ₂ O ₄ /ATP to the biomass precursor was optimized to 1:4, the catalyst exhibited excellent catalytic oxidation performance for toluene degradation, achieving 99% conversion at 300°C along with high stability. The introduction of biochar induced the formation of abundant oxygen vacancies on the spinel surface and effectively suppressed the agglomeration of CuCo ₂ O ₄ particles. Moreover, the rich functional groups on biochar improved toluene adsorption, favouring the subsequent catalytic oxidation. The current study offers a cost-effective strategy for VOC abatement by taking advantage of minerals and biomass.

A synergetic adsorption–photocatalytic-activated Fenton system using an iron-doped g-C₃N₄/GO (GO/Fe-GCN) hybrid with highly efficient performance was established. The highly dispersed iron species with a Fe²⁺/Fe³⁺ ratio (1.67) and mesopores (3.7 nm) with a relative higher specific area and pore volume benefited the reaction efficiency and the contact of organic pollutants with the active sites. In the dynamic adsorption–photo-coordinated Fenton system, the maximum removal rate of GO/Fe-GCN reached 96.5% and equilibrium was 83.6% for Rhodamine B. The GO component not only enhanced the adsorption but also provided a higher efficiency of photo-generated carrier separation and transport. The hybrid structure of GO/Fe-GCN and the high efficiency of circulation of Fe(III)/Fe(II) played an essential role in the synergy of the adsorption–enrichment and the photo-coordinated Fenton reaction. GO/Fe-GCN can also be used to treat complex waste-water containing metallic ions, metal complexes, and organic pollutants, which could allow potential applications in the treatment of water pollution.

A graphene modified epoxy surface tolerant coating was prepared, and the corrosion performance and rust conversion mechanism of the prepared composite coating on rusty carbon steel substrate was investigated. Scanning electron microscope (SEM), X-ray powder diffractometer (XRD), and infrared (IR) spectrum were used to confirmed the iron rust conversion performance by the reaction of phytic acid and rust. electrochemical impedance spectroscopy (EIS), polarization curve, and salt spray test were used to evaluate the corrosion resistance of low surface treatment coatings. Results indicated most of the rust were dissolved and transformed with the reaction of phytic acid and rust on the rusty carbon steel; graphene could effectively improve the compactness and protective performance of the epoxy surface tolerant coating.

The study of the influence of different substances introduced on the same matrix will provide a good guide for the construction of materials with good properties. A series of transitions/lanthanides metal ions doped or co-doped Al₂O₃ aerogel materials with three-dimensional nano porous structure were fabricated by a simple and facile modified sol-gel method. The effect of different transitions/lanthanides metal ions on the microstructure, textural properties, and luminescence properties of Al₂O₃ aerogels were investigated. By co-doping the Al₂O₃ aerogel matrix with Eu³⁺ and Tb³⁺, we fabricated Al₂O₃ aerogel luminescent materials with tunable color emissions under UV excitation. The characterization results showed that the microscopic morphology of these aerogels induced by transitions/lanthanides metal ions were obviously different. Interestingly, Al₂O₃-Eu/Tb (III) and Al₂O₃-Tb/Ce (III) aerogels exhibited a special flower-like structure. It is hoped that our work will offer some efforts for the preparation of functional materials with excellent properties.