Designing high-performance and low-cost electrocatalysts is crucial for the electrochemical production of hydrogen. Dislocation-strained IrNi nanoparticles loaded on a carbon nanotube sponge (DSIrNi@CNTS) driven by unsteady thermal shock in an extreme environment are reported here as a highly efficient hydrogen evolution reaction (HER) catalyst. Experimental results demonstrate that numerous dislocations are kinetically trapped in self-assembled IrNi nanoparticles due to the ultrafast quenching and different atomic radii, which can induce strain effects into the IrNi nanoparticles. Such strain-induced high-energy surface structures arising from bulk defects (dislocations), are more likely to be resistant to surface restructuring during catalysis. The catalyst exhibits outstanding HER activity with only 17 mV overpotential to achieve 10 mA cm−2 in an alkaline electrolyte with fabulous stability, exceeding state-of-the-art Pt/C catalysts. These density functional theory results demonstrate that the electronic structure of as-synthesized IrNi nanostructure can be optimized by the strain effects induced by the dislocations, and the free energy of HER can be tuned toward the optimal region. 相似文献
The use of natural polymer to prepare degradable films is a sustainable production concept that can improve resource utilization and reduce the environmental pollution caused by traditional packaging waste or another field. Here, a regenerated cellulose film was prepared through the N-methylmorpholine-N-oxide (NMMO) cellulose system. The most important advantage of the developed film is that it has air barrier and moisture conduction character, because the surface of films is dense and does not allow small molecules like oxygen to pass through, but water molecules can move freely in the film by means of hydrogen bonds. This shows that the cellulose film has applications in textiles, food preservation, medicine and other fields. Significantly, the film has good tensile strength (maximum strength reaches 149.5 MPa) and light transmittance (more than 80% at 600 nm). Moreover, the effect of coagulation bath concentration, temperature and the content of glycerin on film strength was discussed.
