Xinxin Guan

Antibiotic-based wastewaters seriously endanger human health and damage the ecological environment, and photocatalytic degradation is a desirable strategy for eliminating these contaminants in water. Therefore, developing a proper catalyst for the photodegradation of antibiotics, including ciprofloxacin (CIP), is of great importance. In this study, novel Ag₂S/Zn²⁺-decorated graphitic carbon nitride (AZCN for short) type-II heterojunctions are constructed through a precipitation–calcination procedure. The high porosity with a specific surface area of 133.5 m² g⁻¹, as well as the positive synergy between Ag₂S- and Zn²⁺-decorated graphitic carbon nitride (abbreviated as ZCN), enhance incident light harvesting, increase the adsorption capacity for reactant molecules, favor mass transfer and promote the separation and transport of photoinduced carriers, therefore improving the degradation efficiency of CIP. Specifically, the degradation efficiency of CIP (50 mL, 10 mg L⁻¹) over 2.5% AZCN (10 mg) is 18.1%, 43.1% and 55.7% within 60 min of irradiation using near-infrared light, visible light and simulated solar light, respectively. Moreover, it displays satisfactory recycling stability and excellent universality. This research not only develops a promising heterojunction photocatalyst but also offers some valuable insights in water remediation.

Sodium ion batteries have attracted extensive attention due to their earth-abundant elements and potential for low cost. Iron-based materials not only satisfy these demands but also have high theoretical capacities and are of great commercial value. It is, therefore, necessary to conquer the problems of iron sulfide, including the synthesis method and insufficient cycle stability, from a practical perspective; however, only a few studies have focused on these points. In this work, FeS nanocrystals embedded in a carbon network (FeS@C) were prepared by a homogeneous carbothermal reduction strategy. The advantages of this preparation method are as follows: (1) low-cost and abundant raw materials, (2) green synthesis method without releasing sulfide, (3) simple production processes, and (4) easy large-scale production. The as-synthesized FeS@C demonstrates a long cycle life (97.6%, 3000 cycles) with relatively high initial coulombic efficiency (ICE), high capacity, and excellent rate capacity. The application of FeS@C was further confirmed via a pouch full cell.

A series of composites consisting of anatase TiO₂ nanocrystals and three-dimensional (3D) graphene aerogel (TiO₂–GA) were self-assembled directly from tetrabutyl titanate and graphene oxides via a one-pot hydrothermal process. TiO₂ was found to uniformly distribute inside the 3D network of GA in the resulting composites with large surface areas (S_BET > 125 m² g⁻¹) and high pore volumes (V_p > 0.22 cm³ g⁻¹). In comparison with GA and TiO₂, the composites possessed much higher adsorption capacities and visible light photocatalytic activity in the degradation of rhodamine B (RhB). With an initial concentration of 20.0 mg L⁻¹ of RhB, the adsorptive decolourization of RhB was as high as 95.1% and the total decolourization value reached up to 98.7% under visible light irradiation over 5.0 mg of the resulting composites. It was elucidated that the physical and chemical properties of the TiO₂–GA composites could be ascribed to their unique 3D nanoporous structure with high surface areas and the synergetic activities of graphene nanosheets and TiO₂ nanoparticles.

In this study, novel hierarchical rose-like Cu_1.8Se microspheres with a porous three-dimensional (3D) framework were successfully synthesized by using a one-pot in situ growth method at low temperature (60 °C). The Cu_1.8Se microspheres covered the surface of the 3D porous framework. The formation mechanism was investigated in detail by adjusting the volume ratio of DMF and EDA, as the blend solvents, and the reaction time. Then, the chemical composition of the Cu_1.8Se microspheres was altered by Ag⁺ exchange without changing their morphology and structure. In this way, the binary Cu_1.8Se was efficiently converted into the ternary CuAgSe. Notably, the band gap of materials was tuned continuously from 3.83 eV to 3.03 eV, and CuAgSe was produced continuously by adjusting the replacement time. This work provides a novel concept and a simple method that can serve as a good reference for improving the performance of tunable materials and the preparation of multielement alloy materials.