Novel nanofiber-enhanced SPEEK proton-exchange membranes with high conductivity and stability

Construction of flexible porous 3D biochar based on electrospun rice straw-derived cellulose acetate with excellent adsorption properties toward organic pollutants

Cellulose was extracted from rice straw waste by the intergrated technique of C2H5OH/H2O, dilute alkali treatment and H2O2 bleaching process, and rice straw-derived cellulose acetate was obtained by the acetylation reaction of cellulose. Flexible porous 3D biochars were constructed by the electrospinning, NaBH4 foaming and calcination process. Effects of calcination temperature, adsorption time, pH, pollutant concentration, interfering anions, and cycle times on the adsorption performance of 3D biochar were systematically investigated. 900 °C was the best calcination temperature for preparing 3D biochar, which possessed the largest specific surface area (524m2g-1) and maximum adsorption capacity (149.266 mg/g) toward 10-60 mg/L MB. Its adsorption capacity in neutral (142.870 mg/g) and alkaline (131.075 mg/g) environments was bigger than that in acidic environments (69.867 mg/g). 3D-C900 biochar also has different adsorption capacity toward other dyes and antibiotics (MB 142.870, TC 107.200, RhB 70.110, MO 55.640 mg/g). The interfering anions had limited effect on its adsorption capacity and the removal efficiency of 3D-C900 biochar remained above 86.48 % after 5 cycles. The proposed 3D biochar realizes the high-value utilization of agriculture waste rice straw resources in the direction of water purification, which had potential applications in the fields of wastewater treatment, heavy metal ion adsorption and energy storage.

Advances in the Application of Sulfonated Poly(Ether Ether Ketone) (SPEEK) and Its Organic Composite Membranes for Proton Exchange Membrane Fuel Cells (PEMFCs)

This review discusses the progress of research on sulfonated poly(ether ether ketone) (SPEEK) and its composite membranes in proton exchange membrane fuel cells (PEMFCs). SPEEK is a promising material for replacing traditional perfluorosulfonic acid membranes due to its excellent thermal stability, mechanical property, and tunable proton conductivity. By adjusting the degree of sulfonation (DS) of SPEEK, the hydrophilicity and proton conductivity of the membrane can be controlled, while also balancing its mechanical, thermal, and chemical stability. Researchers have developed various composite membranes by combining SPEEK with a range of organic and inorganic materials, such as polybenzimidazole (PBI), fluoropolymers, and silica, to enhance the mechanical, chemical, and thermal stability of the membranes, while reducing fuel permeability and improving the overall performance of the fuel cell. Despite the significant potential of SPEEK and its composite membranes in PEMFCs, there are still challenges and room for improvement, including proton conductivity, chemical stability, cost-effectiveness, and environmental impact assessments.

Sulfonated polybenzothiazole cathode materials for Na-ion batteries

A new flexible aromatic polymer sulfonated polybenzothiazole (sPBT-SE) with sulphone and ether units is reported as an advanced cathode material for storing Na+, which delivers a high discharge capacity of 103 mA h g−1 after 350 cycles at 30 mA g−1.