Metal organic frameworks (MOFs) have been rapidly developed in the application of electrode materials due to their controllable morphology and ultra-high porosity. In this research, flower-like layered nickel-based bimetallic MOFs microspheres with different metal central ions were synthesized by solvothermal method. Compared with Ni-MOFs, the optimization of the specific capacitance of NiCo-MOFs and NiMn-MOFs was been confirmed. For example, the specific capacitance of NiCo-MOFs can reach 882 F·g⁻¹ at 0.5 A·g⁻¹ while maintaining satisfactory cycle life (the specific capacity remains 90.1% of the initial value after 3000 charge-discharge cycles at 5 A·g⁻¹). In addition, the NiCo-MOFs//AC HSCs, which are composed of NiCo-MOFs and activated carbon (AC), achieved a maximum energy density of 18.33 Wh·kg⁻¹ at a power density of 400 W·kg⁻¹, and showed satisfactory cycle life (82.4% after 3000 cycles). These outstanding electrochemical properties can be ascribed to the synergistic effect between metal ions, the optimized conductivity, and the unique layered stacked flower structure, which provides a smooth transmission channel for electrons/ions. In addition, this research gives a general method for the application of MOFs in the field of supercapacitors.

A novel inorganic polymer flocculant, biopolymeric ferric sulfate (BPFS), was prepared by immobilization technology of microorganisms and by oxidation of ferrous sulfate using domestic Thiobacillus ferrooxidans (T. f) under acidic condition. T. f was isolated on the agarose single-plate medium, which exhibited an unusual trait on the utilization of low concentration of the nitrogen source and phosphorus as the nutrient substance. Under the optimal conditions, the microorganism could grow and reproduce normally and maintain the strong catalytic oxidation activity to Fe²⁺. The immobilization of T. f on the polyurethane as the support matrix was investigated. Cycling batch operation was applied to the preparation of 40 kg/m³, 60 kg/m³, and 80 kg/m³ BPFS when the optimal conditions are pH value of 1.8, circulation flow rate of 0.28–0.30 L/h, and reaction temperature of 28 ± 1°C. When the prepared BPFS and SPFS (solid biopolymeric ferric sulfate) were used to dispose Songhua River water, the removal rate of turbidity and COD_Mn of BPFS was slightly better than that of SPFS. The removal efficiencies of turbidity and COD_Mn by BPFS could reach 93.9% and 79.7%, respectively. The result suggests that the BPFS has good flocculating activity.

Diatomite (DE) is a widely used adsorption material in wastewater treatment due to its cost-effectiveness, high porosity, and stability. To improve its adsorption properties, we synthesized biopolymeric ferric sulfate (BPFS) through biocatalytic oxidation, known for its efficient removal of organic compounds. In this study, we prepared a novel adsorbent, biopolymeric ferric sulfate-modified diatomite (BPFS-DE), by modifying DE with BPFS. We characterized DE and BPFS-DE using various techniques, including scanning electron microscopy (SEM), N₂ adsorption–desorption, and X-ray diffraction (XRD), to assess their physical and chemical properties before and after modification. We investigated the adsorption performance of BPFS-DE for acid chrome blue K (ACBK) and analyzed the adsorption mechanisms. Our results revealed that modification with BPFS increased the porosity and specific surface area of DE. BPFS-DE exhibited remarkable adsorption capabilities (98.6%) for ACBK under pH 6.0, 30 °C, and a 30-minute adsorption time. Langmuir adsorption isotherm models demonstrated excellent agreement (R = 0.9896) with the adsorption data, highlighting the effectiveness of the BPFS-DE adsorbent. Furthermore, the pseudo-second-order reaction kinetics model provided a better fit (R = 0.9075) than the pseudo-first-order model, accurately reflecting the adsorption process. The adsorption process was found to be spontaneous and exothermic. Notably, BPFS-DE outperformed DE in terms of adsorption efficiency. The synthesized BPFS-DE emerges as a promising adsorbent for treating industrial wastewater contaminated with dyes.