Residual drug pollutants in water environments represent a severe risk to human health, so developing a cheap, environmentally friendly, and effective photocatalyst to deal with them has become a hot topic. Herein, a magnetically separable Fe₃O₄@TiO₂/g-C₃N₄ photocatalyst with a special heterojunction structure was fabricated, and its photocatalytic performance was assessed by degrading tetracycline (TC). Compared to Fe₃O₄@TiO₂, the synthesized Fe₃O₄@TiO₂/g-C₃N₄ exhibited superior TC degradation performance, which was primarily ascribed to the heterojunction formed between TiO₂ and g-C₃N₄ and its ability to enhance the visible light absorption capacity and reduce the photoinduced electron/hole recombination rate. Moreover, a free radical capture experiment further confirmed that ·O₂⁻ and h⁺ are the predominant components in the TC degradation reaction. Under UV–Vis irradiation, the TC degradation rate escalated to as high as 98% within 120 min. Moreover, Fe₃O₄@TiO₂/g-C₃N₄ was demonstrated to be easily recovered by magnetic separation without any notable loss even after five cycles, showing exceptional stability and reusability. These findings indicate that Fe₃O₄@TiO₂/g-C₃N₄ is a promising photocatalyst for environmental remediation that may provide a sustainable approach to degrading antibiotic pollutants in wastewater.

Spherical and monodispersed Dy³⁺/Eu³⁺ co-activated SiO₂@Gd₂O₃ core-shell phosphors with tunable multicolor luminescence have been successfully prepared via a facile urea assisted precipitation method.

Superparamagnetic Fe₃O₄ particles have been synthesized by solvothermal method, and a layer of dense silica sol polymer is coated on the surface prepared by sol-gel technique; then La(OH)₃ covered the surface of silica sol polymer in an irregular shape by controlled in situ growth technology. These magnetic materials are characterized by TEM, FT-IR, XRD, SEM, EDS and VSM; the results show that La(OH)₃ nanoparticles have successfully modified on Fe₃O₄ surface. The prepared Fe₃O₄@La(OH)₃ inorganic polymer has been used as adsorbent to remove phosphate efficiently. The effects of solution pH, adsorbent dosage and co-existing ions on phosphate removal are investigated. Moreover, the adsorption kinetic equation and isothermal model are used to describe the adsorption performance of Fe₃O₄@La(OH)₃. It was observed that Fe₃O₄@La(OH)₃ exhibits a fast equilibrium time of 20 min, high phosphate removal rate (>95.7%), high sorption capacity of 63.72 mgP/g, excellent selectivity for phosphate in the presence of competing ions, under the conditions of phosphate concentration 30 mgP/L, pH = 7, adsorbent dose 0.6 g/L and room temperature. The phosphate adsorption process by Fe₃O₄@La(OH)₃ is best described by the pseudo-second-order equation and Langmuir isotherm model. Furthermore, the real samples and reusability experiment indicate that Fe₃O₄@La(OH)₃ could be regenerated after desorption, and 92.78% phosphate removing remained after five cycles. Therefore, La(OH)₃ nanoparticles deposited on the surface of monodisperse Fe₃O₄ microspheres have been synthesized for the first time by a controlled in-situ growth method. Experiments have proved that Fe₃O₄@La(OH)₃ particles with fast separability, large adsorption capacity and easy reusability can be used as a promising material in the treatment of phosphate wastewater or organic pollutants containing phosphoric acid functional group.

With broad application prospects in electronic systems, supercapacitors are under ongoing development to have higher flexibility, portability, and integration. Although flexible supercapacitors have received widespread attention, their further applications are limited as a consequence of low volumetric energy densities. Developing dense film materials with a high specific capacitance and employing them to assemble asymmetric supercapacitors (ASCs) for expanding the working voltage serve as a strategy to break through the limitation. Herein, we report a universal method for preparing porous graphene nanosheets/carbon nanotubes@metal (hydr)oxide (PGNs/CNT@metal (hydr)oxide) composite films with fast ion and electron kinetics via the vacuum-assisted filtration self-assembly technique. The designed channels on the graphene surface accelerate electrolyte ion diffusion in the direction perpendicular to the graphene film. The introduction of CNT@metal (hydr)oxide inhibits the agglomeration of graphene sheets, thereby speeding up electrolyte ion diffusion in the direction parallel to the graphene film. For pseudocapacitive materials with poor conductivity, the internal and external conductance paths established by CNTs and PGNs can facilitate the electron kinetics of the composite. For the asymmetric supercapacitor assembled with PGNs/CNT@Ni(OH)₂ and PGNs/CNT@Fe₂O₃ as the positive and negative electrodes, respectively, its volumetric energy density reached 114.3 W h L⁻¹ in 1 M KOH aqueous electrolyte and even 45 W h L⁻¹ in a solid electrolyte. This rational structure design of electrode materials can provide guidance for the development of energy storage materials with outstanding volumetric performance for flexible supercapacitors.