三维生物质纳米纤维气凝胶的制备及其对染料的催化降解性能研究

Preparation of Three-Dimensional Biomass Nanofiber Aerogels and Its Performance of Catalytic Degradation on Dyes

为高效去除污水中的有机染料,以生物质聚乳酸(PLA)纳米纤维和海藻酸钠(SA)为原料、氧化石墨烯(GO)为催化剂、Ca^(2+)为交联剂,通过冷冻干燥技术制备了全生物质纳米纤维气凝胶(PLA/SA-GO),经氢碘酸(HI)还原后得到PLA/SA-RGO气凝胶,并对其结构和成分进行表征.同时,将PLA/SA-RGO用于催化氧化H_(2)O_(2)以降解酸性橙Ⅱ(AO2),探讨了pH值、样品用量、H_(2)O_(2)浓度等对染料催化降解性能的影响.结果表明:聚PLA纳米纤维相与海藻酸相具有较好的相容性;对比还原前后的气凝胶发现,对AO2的去除率从12%提高到了80%以上,且pH=9时去除率接近100%;5次循环后的复合气凝胶依然保留较好的催化降解效果.

In order to efficiently remove organic dyes from sewage,biomass polylactic acid(PLA)nanofibers and sodium alginate(SA)were used as raw materials,Graphite oxide(GO)as the catalyst,and Ca^(2+)as the cross-linking agent.The whole biomass nanofiber aerogel(PLA/SA-GO)was prepared by freeze-drying technology.After being reduced by hydroiodic acid(HI),the structure and composition of the obtained PLA/SA-RGO were characterized.Besides,it was used to catalyze the oxidation of H_(2)O_(2)to degrade acid orangeⅡ(AO2),and the effects of pH value,sample dosage,and H_(2)O_(2)concentration on the catalytic degradation performance of dyes were explored.The results showed that the PLA nanofiber phase and alginic acid phase show good compatibility.Compared with the unreduced aerogels,the reduced aerogels can increase the removal rate of AO2 from 12%to more than 80%.At the same time,the removal rate of dyes under alkaline conditions is close to 100%,and the repeatability study showed that the composite aerogels still retain a good catalytic degradation effect after five cycles.