The construction of NiFe-based composites on foam metal is an advanced strategy to design high-performance catalysts for hydrogen evolution reaction (HER) and oxygen evolution reaction (OER). Herein, we chose Fe foam (FF) as the substrate, which was first modified by anodic electrodeposition to form a porous and loose FeS x / FeO x layer. This modified layer facilitates the construction of nanoflower-structured NiFeS 2 /NiFe 2 O 4 composites with large electrochemical active surface area, higher Ni content and enhanced ratio of Ni 3 + to Ni 2+ , compared with the sample fabricated by direct etching FF. The prepared NiFeS 2 /NiFe 2 O 4 /FF electrode only requires overpotentials of 242 and 273 mV to achieve current densities of 100 and 500 mA cm⁻ 2 for OER, respectively. It also possesses faster reaction kinetics with a low Tafel slope of 31.12 mV dec −1 and superior durability without potential reduction for 200 h at a large current density of 500 mA cm⁻ 2 . Meanwhile, the performance of overall water splitting cell assembled with NiFeS 2 /NiFe 2 O 4 /FF is better than that of cell based on the noble metal Pt/C/FF- |RuO 2 /FF. This work provides a simple and cost-effective strategy for constructing efficient electrocatalysts, making it promising for large-scale industrial applications in alkaline water electrolysis.
The frequent oil spills and the discharge of oily wastewater have a severe impact on the sustainability of the environment and the ecosystem, which make an urgent need to develop a low-cost, mechanically stable, non-toxic, eco-friendly, corrosion-resistant, and highly efficient oil/water separation materials. Hence, a 3D superhydrophobic foam iron (SHFI) was prepared for oil/water continuous separation, zinc–iron (ZI) coating being electrodeposited on the 3D foam iron (FI) in an alkaline cyanide-free glycerol electrolytic bath, followed by the modification of tetradecanoic acid. Besides superhydrophobicity (Water contact angle: 158° and Sliding angle: 2°), the SHFI was provided with good anti-corrosion, excellent chemical stability, and outstanding mechanical stability against 100 cycles of abrasive paper (800 grit) abrasion at 5 kPa. Furthermore, the SHFI is able to achieve high efficiency of oil/water separation up to 99.3%. More importantly, the 3D SHFI can be designed into a device for oil/water continuous separation. The whole process of the preparation of SHFI is facile, green, and economic. Predictably, the 3D SHFI and the designed device will be promising for the actual oil/water continuous separation.
Microbial fuel cell is a promising way for renewable energy recovery. The direct conversion of urine into electricity through MFC has been tested, considering that urine has rich organic substances and high conductivity, demonstrating dual benefits for electricity generation and urine treatment as a feasible method. However, it still suffers from several constraints relating to anodes, including limited bacterial loading capacity and inferior extracellular electron transfer efficiency. Substantial efforts have been made to improve electricity production, especially to develop new anodes. In this study, we prepared a new composite anode (SC-FeNi) and used it in an MFC reactor to recover energy from urine. The power density of the SC-FeNi anode could reach 524.93 mW·m −2 when using synthetic urine and increased to 1720.1 mW·m −2 when replaced with undiluted human urine, which was the highest power density in monomer MFC fueled with urine to the best of our knowledge. SC-FeNi had high conductivity (12.29 S·m −1 ), large specific surface area (1236.417 m²·g −1 ), and enriched high microorganism density (312.04 ± 15.4 mg·cm − ³). The stable power generation period in batch mode reached 288 h. This experiment verified that combining foam metal and disordered porous carbon as MFC electrode materials could generate energy from human urine waste with high efficiency and durability.
危险品化学品经营许可证（带存储）