Nitrogen-doped microporous graphite-enhanced copper plasmonic effect for solar evaporation

Water scarcity is a global challenge,and solar evaporation technology offers a promising and eco-friendly solution for freshwater production.Photothermal conversion materials(PCMs)are crucial for solar evaporation.Improving photothermal conversion efficiency and reducing water evaporation enthalpy are the two key strategies for the designing of PCMs.The desired PCMs that combine both of these properties remain a challenging task,even with the latest advancements in the field.Herein,we developed copper nanoparticles(NPs)with different conjugated nitrogen-doped microporous carbon coatings(Cu@C–N)as PCMs.The microporous carbon enveloping layer provides a highly efficient pathway for water transport and a nanoconfined environment that protects Cu NPs and facilitates the evaporation of water clusters,reducing the enthalpy of water evaporation.Meanwhile,the conjugated nitrogen nodes form strong metal-organic coordination bonds with the surface of copper NPs,acting as an energy bridge to achieve rapid energy transfer and provide high solar-to-vapor conversion efficiency.The Cu@C–N exhibited up to 89.4%solar-to-vapor conversion efficiency and an evaporation rate of 1.94 kgm^(−2) h^(−1) under one sun irradiation,outperforming conventional PCMs,including carbon-based materials and semiconductor materials.These findings offer an efficient design scheme for high-performance PCMs essential for solar evaporators to address global water scarcity.

Effects of collagen fiber addition on the combustion and thermal stability of natural rubber

Collagen fiber(CF)and silane coupling agent-modified collagen fiber(MCF)were used as flame retardant filler for natural rubber(NR)modification.The combustion phenomena and properties of composites blended with different dosages of CF or MCF were compared to elucidate the flame retardant mechanism of the composites.The flame retardancy of NR can be enhanced effectively by increasing nitrogen content(the nitrogen content of CF is about 18%),creating air pockets,and structuring the flame retardant network in the composites.MCF failed to structure a flame retardant network in the composite,indicating that its modification effects of MCF are weaker than those of CF.When CF dosage was 30 wt%,the composite can achieve the best flame retardancy,with limited oxygen index of 29.4% and without smoke and dripping during burning.This study demonstrated a new method for the flame retardant modification of NR.