羥基改質石墨型氮化碳對甲醛氣體降解之研究

Enhance Photocatalytic Activity of Hydroxyl-Modified Graphitic Carbon Nitride for Formaldehyde Degradation

蔡瑋凡(Wei-Fan Tsai)

指導教授 ： 胡哲嘉

中原大學/工學院/化學工程研究所/碩士(2020年)

https://doi.org/10.6840/cycu202000475

摘要

近年來，由於新型冠狀病毒(COVID-19)的傳播，人們對於空氣品質的意識急劇提高。在眾多空氣污染物中，其中以氣態甲醛(HCHO)目前被認為是最常見的室內空氣污染物，會對健康產生許多負面影響，且具有致癌的可能性。在本次研究中，以去除有毒的甲醛氣體為目標，使用不同濃度的氫氧化鈉在回流條件下將石磨型氮化碳(g-C3N4)進行改質，在材料表面接枝羥基以改善石磨型氮化碳，並加入金屬鈉以改善電子傳遞效率，達到更好的光觸媒活性。
透過FTIR, XPS分析證實本次實驗成功於材料表面改質羥基;同時透過XRD, XPS, EDS證實鈉金屬鈉存在於改質後的材料中;UV-vis, PL證實改質後樣品具有更佳的可見光使用率。此外，利用暗室吸脫附及光催化實驗，證實改質後的光觸媒具有更好的甲醛吸附及分解效果，其中以0.2HMCN在可見光照射下，對4.5ppm的甲醛氣體在100分鐘內有超過80 %的去除率。

關鍵字

甲醛移除 ； 石墨型氮化碳 ； 羥基改質

並列摘要

Recently, due to the spread of Coronavirus Disease 2019 (COVID-19), awareness of air quality has risen drastically. Out of all air pollutants, gaseous formaldehyde (HCHO) is currently considered as the most common indoor air pollutant causing numerous negative health effects. In this work, with the goal of removing HCHO, different concentrations of sodium hydroxide were investigated at reflux conditions for the improvement of melamine derived graphitic carbon nitride (MCN) activation. Both adsorption and photocatalytic oxidation experiments were carried out investigating the removal performance of HCHO.
While maintaining the g-C3N4 characteristics in order to maintain the visible-light-driven nature, a hydroxyl-modified surface with Na atoms intercalated into the photocatalyst (0.2HMCN) exhibited a better ability to eliminate HCHO in comparison with the pristine MCN, exhibiting a removal rate of over 80% of HCHO (4.5ppm) in 100 mins under visible light irradiation. The results of the X-ray diffractometer (XRD) pattern, Energy-dispersive X-ray spectroscopy (EDS) analysis and X-ray photoelectron spectroscopy (XPS) of 0.2HMCN confirmed the existence of Na atoms. This provided a new pathway for photoinduced electrons by suppressing the recombination of electron-hole pairs, which was further confirmed by the photoluminescence (PL) spectrum. Moreover, the higher surface area and hydroxyl groups on the materials surface increased the HCHO adsorption performance, which was confirmed by the N2 adsorption-desorption isotherm and Fourier transform infrared spectroscopy (FTIR), respectively.

並列關鍵字

formaldehyde removal ； graphitic carbon nitride ； hydroxyl-modified

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