應用碳量子點/ZnO的納米棒異質結構在可見光下驅動光催化降解一氧化氮

一氧化氮 (NO) 被認為是空氣污染物的主要成分之一，目前已引發酸雨、光化學煙霧等環境問題，甚至可造成人類健康危害。在為解決這些問題而應用的各種技術之中，光催化技術因其能夠在低濃度下降解 NO，且具低處理成本、永續和環境友善性等特性而備受關注。近期的研究結果指出氧化鋅奈米柱(NRs)因其高傳輸電荷效率、高表面積與體積比和高性能等特性，被視為極具發展潛力之光催化劑。然而，目前關於其最佳合成方法的研究仍然甚少，因此本研究通過一步驟溶劑熱法成功合成高性能的氧化鋅納米柱光催化劑，並針對其合成方法參數與特性進行研究。透過X光繞射儀(XRD)、傅立葉轉換紅外光譜儀(FTIR)、掃描電子顯微鏡(SEM)、穿透式電子顯微鏡(TEM)、比表面積與孔隙分布分析儀(BET)和漫反射光譜儀(DRS)等分析，研究生成時間和溫度對氧化鋅納米柱形態和表面積之影響。研究結果顯示在 100 ℃ 處理 6 小時合成的氧化鋅納米柱具最佳效能，其對 NO 的去除率最高（太陽光下為 78.8%，可見光下為 62.2%）。此外，附載在氧化鋅納米柱表面的碳量子點在太陽光和可見光照射下，可有效提升光吸收和 NO 降解效率，分別提高了 11.5% 和 7.7%。另外本研究經由活性物質捕獲實驗和ESR分析，提出光催化降解NO之機制。而在穩定性實驗中，結果亦指出碳量子點 /氧化鋅納米柱在可見光照射下，表現出高度穩定性，在重複使用 5 次後效能僅降低 7.7%。

關鍵字

一氧化氮；光催化；氧化鋅納米柱；碳量子點/氧化鋅納米柱；太陽光；可見光

並列摘要

Nitric oxide (NO) is regarded as the main component of air pollutant which has been causing environmental problems such as acid rain, photochemical smog and even human health. Among various techniques deployed to solve the problems, photocatalysis has attracted much attention due to its ability to degrade NO at low concentration combined with a cheap, sustainable and environmentally friendly process. Recent studies have proven that ZnO Nanorods (NRs) may be applied as potential photocatalyst due to their high transport charge efficiency, surface-to-volume ratio, and high performance. However, there is still less information regarding its optimum synthesize methods. In this study, high-performance ZnO NRs photocatalyst were successfully synthesized via one-step solvothermal. The effect of growth times and temperatures on the morphology and surface area of ZnO NRs are investigated through XRD, FTIR, SEM, TEM, BET, and DRS. The results show that the ZnO NRs synthesized at 100oC for 6 hours are the best samples with the highest photocatalytic removal efficiency of NO (78.8% under solar light and 62.2% under visible light). In addition, CQDs supported on the surface of ZnO NRs greatly improve the efficiency of light absorption and NO degradation by up to 11.5% and 7.7% respectively with solar and visible light irradiation. Furthermore, the mechanism of photocatalysis of NO degradation was also suggested through the active species trap experiment and ESR analysis. Finally, CQDs/ZnO NRs showed high stability under visible light irradiation, with only 7.7% reduction after 5 reuses.

並列關鍵字

Nitric oxide ； Photocatalysis ； ZnO nanorods ； CQDs/ZnO nanorods ； solar light ； visible light

參考文獻

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