有機染料主要用於紡織及食品加工中,目前染料的種類已超過了十萬種,由於其非生物降解性、對水生生物高毒性及對人體的致癌性,再加上,染料廢水具有色澤深且酸鹼性強等特點,因此一直是廢水處理中的難題。 本研究使用熱液法 (solvothermal method)將氧化鋅進行摻雜,使氧化鋅能隙縮小,進而可利用可見光進行光催化反應,接著再以原位聚合法 (in-situ polymerization)與聚苯胺做結合形成有機/無機複合物,使其同時具有氧化鋅的特性與聚苯胺的優勢,進而讓材料之應用範圍更加廣泛。另外,以此材料進行染料的去除研究,欲去除之染料為酸性與鹼性染料,前者選用活性黑KN-B (reactive black 5,RB5),後者則以亞甲基綠氯化鋅複合鹽 (methylene green zinc chloride double salt,MG)做代表,進行吸附及可見光光催化之研究。 結果顯示,摻氮氧化鋅/聚苯胺複合物是由摻氮氧化鋅表面包覆一層聚苯胺而形成的。在去除RB5染料的實驗中,ZnO-N/PANI(1:1)擁有最好的總去除率(60.5%),24小時的吸附去除率為44.4%,而6小時的光催化降解率為16.1%,其最大吸附量是221 mg/g,且整個過程中並無副產物產生。在去除MG染料的實驗中,ZnO-N/PANI(1:1)具有最好的總去除率 (71.8%),24小時的吸附去除率為17.4% (非最佳,最佳的為PANI,其吸附去除率為36.0%),而6小時的光催化降解率為54.4%,其最大吸附量是9.80 mg/g,且整個過程中並無副產物產生,摻氮氧化鋅/聚苯胺複合物在可見光下可加速RB5和MG染料的分解。
More than one hundred thousand kind of organic dyes are used in textile and food industries. In wastewater treatment, organic dyes are big problems due to their non-biodegradability and high toxicity to aquatic creatures and carcinogenic effects on humans, as well as the dark color and extreme pH. In this study, nitrogen-doped zinc oxide (ZnO-N) were fabricated by solvothermal method. The photocatalyst ZnO-N could process chemical reaction under visible light. Further, ZnO-N was combined with polyaniline (PANI) by in-situ polymerization to form inorganic-organic material─nitrogen-doped zinc oxide with polyaniline (ZnO-N/PANI) composite. The composite had advantage of PANI and ZnO-N so it can be widely used. In addition, reactive black 5 (RB5) and methylene green zinc chloride double salt (MG) dyes were tested by ZnO-N/PANI under visible light to evaluate its effect. The results showed PANI and ZnO-N had formed a composite in which the ZnO-N was embedded within the polymer matrix. For RB5 dye removal experiment, 60.5% of total removal efficiency was the highest for ZnO-N/PANI(1:1). The adsorption efficiency is 44.4% for 24 hours and its photo-degradation efficiency is 16.1% for 6 hours. The maximum adsorption capacity is 221 mg/g. For MG dye removal experiment, 71.8% of total removal efficiency was the highest for ZnO-N/PANI(1:1). The adsorption efficiency is 17.4% for 24 hours and its photo-degradation efficiency is 54.4% for 6 hours. The maximum adsorption capacity is 9.80 mg/g. The ZnO-Z/PANI composite will accelerate the degradation of RB5 and MG under visible light.