Fabrication of CdS/Ti3C2/g-C3N4NS Z-scheme composites with enhanced visible light-driven photocatalytic activity

In situ fabrication of Z-scheme C3N4/Ti3C2/CdS for efficient photocatalytic hydrogen peroxide production

Photocatalysis is a potential technology to produce hydrogen peroxide with low energy consumption and no pollution. However, when using traditional photocatalysts it is hard to meet the requirements of wide visible light absorption, high carrier separation rate and sufficient active sites. Graphitic carbon nitride (g-C3N4) has great potential in the photocatalytic production of hydrogen peroxide, but its photocatalytic performance is limited by a high carrier recombination ratio. Here, we fabricated the Z-Scheme heterojunction of C3N4/Ti3C2/CdS in situ. The large specific surface area of C3N4 can provide plenty of reactive sites, and the absorption efficiency under visible light is improved with the addition of Ti3C2 and CdS. The better conductivity of Ti3C2 reduces the charge transfer resistance. With the increase of surface charge carriers, the width of the space charge region decreases and the photocurrent density increases significantly. Under visible light irradiation, the H2O2 yield of the ternary photocatalyst reaches 256 μM L-1 h-1, which is about 6 times that of pristine C3N4. After three cycles, the high photocatalytic efficiency can still be maintained. In this paper, the reaction mechanism of photocatalytic hydrogen peroxide production by the C3N4/Ti3C2/CdS composite material is proposed through an in-depth study of energy band theory, which provides a new reference for the design and preparation of high-performance materials for photocatalytic hydrogen peroxide production.

Two-dimensional Ti3C2 MXene-derived Ti3C2-Ti2C-TiO2 materials for improved diclofenac sodium adsorption performance

This paper aims to prepare an adsorbent based on MXene material for adsorbing diclofenac sodium (DCF). In this paper, Ti₃C₂-MXene was prepared by etching Ti₃AlC₂ with hydrofluoric acid (HF). Ti₃C₂ was subjected to a convenient and simple solvothermal treatment. TiO₂ and Ti₂C were formed during the solvothermal process. According to the results of FT-IR and XRD, the formation of TiO₂ and Ti₂C will increase the interlayer spacing of the prepared Ti₃C₂-12 h, thereby improving the adsorption performance of MXenes. The main factors affecting the adsorbent, the maximum adsorption capacity, and the interaction between the two factors were analyzed by single-factor experiment, orthogonal experiment, and response surface analysis. The maximum DCF adsorption capacities of Ti₃C₂ and Ti₃C₂-12 h are 201 mg/g and 395 mg/g, respectively. MXene made from HF can absorb DCF under various pH conditions and maintain a high adsorption rate, which has important applications in environmental protection.