The increasing concentration of residual ciprofloxacin (CIP) can cause potential harm to the environment. Photocatalysis has been regarded as an effective method for the degradation of CIP. Bi/BiVO₄ with excellent photocatalytic performance was synthesized partial reduction with NaBH₄. The structure, morphology, composition, and optical performance of BiVO₄ and Bi/BiVO₄ were characterized by a variety of techniques. The results showed that the Bi/BiVO₄ exhibits high photocatalytic activity in the degradation of CIP. Comparison of BiVO₄ and Bi/BiVO₄ has lower photoluminescence intensity and higher photocurrent responses intensity. The introduction of Bi made Bi/BiVO₄ have a higher charge separation efficiency and generate more active free radicals. In addition, the radical trapping experiments revealed that superoxide free radicals and holes were the main active free radicals during the degradation of CIP. The pathway of CIP degradation was investigated through high performance liquid chromatography-mass spectrometry, and a possible degradation mechanism was proposed.

A Bi₂WO₆/BiVO₄ composite photocatalyst was synthesized that can promote the separation and transfer of photogenerated carriers and effectively degrade organic pollutants under visible light.

A double-heterojunction-structure photocatalyst g-C ₃ N ₄ /(101)-(001)-TiO ₂ with Z-system and surface heterojunction, was synthesized, which can effectively promote the separation of photogenerated e ⁻ –h ⁺ pairs and the degradation of organic pollutants.

A novel magnetic carbon–silicon composite (Fe-HH-CGFS) was prepared from solid waste coal gasification fine slag (CGFS) by a two-step acid leaching and one-step chemical co-precipitation process, which was optimized using a 3-factor, 3-level Box–Behnken design and then analyzed for correlation. Fe-HH-CGFS was characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), Brunauer–Emmett–Teller (BET), thermal gravimetric analysis (TGA), and vibrating sample magnetometer (VSM) measurements. The results demonstrated that Fe-HH-CGFS had a reverse spinel structure with an average particle size of 5.14 nm, exhibiting a microporous/mesoporous structure with a specific surface area (SSA) of 196.84 m² g⁻¹ and pore volume of 0.346 cm³ g⁻¹. Furthermore, Fe-HH-CGFS could achieve 97.59% removal efficiency of rhodamine B (RhB) under the optimal conditions: an initial concentration of RhB of 100 mg L⁻¹, an adsorption time of 60 min, and a dosage of Fe-HH-CGFS of 1.0 g L⁻¹. The pseudo-second-order model and the Langmuir isotherm satisfactorily described the adsorption behavior. The results indicated that the RhB removal process was a single-molecule layer endothermic adsorption, which is dominated by chemical adsorption reactions. This work is expected to provide an alternative route for the high-value utilization of CGFS and offer a valuable insight for the recycling of other solid wastes, aligning with the green development concept of “treating wastes with wastes”.

Coal gasification fine slag (FS), a kind of by-product of coal chemical industry, was recovered for the preparation of functional adsorbents by acid leaching process, which was orthogonally optimized by HCl, HNO₃, HF, HAc, and H₂SO₄. Methylene blue (MB) was used to evaluate the performance of functional adsorbents. The results demonstrated that 57.6% of the leaching efficiency (R_LE) and 162.94 mg/g of adsorption capacity (C_AC) of MB were achieved under the optimal conditions of HNO₃ of 2.0 mol/L, acid leaching time of 2.0 h, and acid leaching temperature of 293K. The detections on X-ray Diffraction (XRD), Scanning Electron Microscope (SEM), Fourier Transform Infrared Spectroscopy (FTIR), and BET surface area (SBET) indicated that the synthesized functional adsorbents were characterized by mesoporous materials. The good fitting of adsorption process using pseudo-second-order and Langmuir models demonstrated that the chemisorption contributed to MB removal. The results of thermodynamics further revealed that the adsorption process of MB occurred spontaneously due to the exothermic properties. The work is expected to develop a novel and cost-effective strategy for the safe disposal of FS, and potentially offer an alternative pathway to increase the additional value for the coal chemical industry.

Coal gasification crude slag (CGCS) is the side-product of the coal gasification process, and its effective utilization has attracted great attention.