可控碳化废弃聚丙烯制备镍/碳纳米材料用于高效光蒸气转换

利用太阳能实现光蒸气转化是一项极具前景的技术,可应用于海水脱盐和淡水制备等领域.然而,从工业的角度来看,制备低成本、高效率的光热材料仍具有挑战性.本文利用聚离子液体(PIL)和氧化镍(Ni O)作为复合催化剂,实现了聚丙烯(PP)的可控碳化,并制备了镍/碳纳米材料(Ni/CNM).研究结果表明,加入微量的PIL可实现对Ni/CNM形貌和织态结构的调控.Ni/CNM由杯状碳纳米管(CS-CNT)和梨形镍纳米颗粒组成,二者在太阳光吸收上的协同作用使得Ni/CNM具有优异的光热转换性能.此外,Ni/CNM具有较高的比表面积和丰富的微/介/大孔,其构建的三维多孔网络可为水和蒸气的高效传输提供通道.光吸收高、水传输快和热导率低等优势,使Ni/CNM的水蒸发速率高达1.67 kg m^-2h^-1,光-蒸气转换效率高达94.9%,且重复使用10次后性能依然保持稳定.该材料同时适用于染料废水、海水和油/水乳化液等水质的纯化.其中,海水中金属离子的去除效率高达99.99%,染料去除率>99.9%.更重要的是,材料的光蒸气转换性能优于最新报道的碳基光热材料.此工作不仅提出了一种可将废弃聚合物转化为先进的金属/碳杂化物的可持续方法,同时也有助于太阳能利用和海水淡化领域的进一步研究.

High-performance solar vapor generation of Ni/carbon nanomaterials by controlled carbonization of waste polypropylene

Solar vapor generation is emerging as a promising technology using solar energy for various applications including desalination and freshwater production.However,from the viewpoints of industrial and academic research,it remains challenging to prepare low-cost and high-efficiency photothermal materials.In this work,we report the controlled carbonization of polypropylene(PP)using NiO and poly(ionic liquid)(PIL)as combined catalysts to prepare a Ni/carbon nanomaterial(Ni/CNM).The morphology and textural property of Ni/CNM are modulated by adding a trace amount of PIL.Ni/CNM consists of cup-stacked carbon nanotubes(CS-CNTs)and pear-shaped metallic Ni nanoparticles.Due to the synergistic effect of Ni and CS-CNTs in solar absorption,Ni/CNM possesses an excellent property of photothermal conversion.Meanwhile,Ni/CNM with a high specific surface area and rich micro-/meso-/macropores constructs a threedimensional(3 D)porous network for efficient water supply and vapor channels.Thanks to high solar absorption,fast water transport,and low thermal conductivity,Ni/CNM exhibits a high water evaporation rate of 1.67 kg m^-2 h^-1,a solar-to-vapor conversion efficiency of 94.9%,and an excellent stability for 10 cycles.It also works well when converting dyecontaining water,seawater,and oil/water emulsion into healthy drinkable water.The metallic ion removal efficiency of seawater is 99.99%,and the dye removal efficiency is>99.9%.More importantly,it prevails over the-state-of-art carbonbased photothermal materials in solar energy-driven vapor generation.This work not only proposes a new sustainable approach to convert waste polymers into advanced metal/carbon hybrids,but also contributes to the fields of solar energy utilization and seawater desalination.