以化學氣相沉積法合成負載於中孔洞之鈣鈦礦材料應用於光催化二氧化碳還原

Abstract

本研究以化學氣相沉積法結合中孔洞及碳材，在高溫反應 (700-900°C)下及不同反應時間(10-90 分鐘)，將具有空氣及水氣敏感之鈣鈦礦結構附載於中孔洞材料中，並調控生長CsPbBr3/Cs4PbBr6異質結構，並且研究空氣及抽真空對於異質結構發光之影響。為避免孔洞外生長所造成鈣鈦礦氧化、水解等副反應，本研究利用高溫裂解界面活性劑或乙烯氣體以生長表面碳材(2.5-5 mmol/g SiO2)，不僅將鈣鈦礦前驅物有效沉積，並同步生長及保護鈣鈦礦奈米粒子，經由X光繞射實驗及謝樂擬合經驗式證實奈米粒子 (<2 nm)包覆於複合材料中。此複合材料經由紫光 (405 nm)照射後，原鈣鈦礦螢光強度粹滅18倍，顯示其具有電荷分離效果。 在二氧化碳還原實驗中，我們利用即時反應偵測氫氣、甲烷及一氧化碳生成，同時優化二氧化碳流速 (10-50 sccm)對於殘留空氣及反應時間 (0-6小時)之影響，比較三種孔洞載體 (MZNs、Ar-MZNs、MGNs)在不同溫度 (700-900oC)負載鈣鈦礦材料進行二氧化碳還原反應。其中以乙烯裂解產生之MGNs在UV光(365 nm)下具有最佳的催化效率，其中氫氣、甲烷及一氧化碳的產生量較初始值提升13.3 %、14.7 %、10.0 %，此結果回應上述螢光淬滅之實驗結果，同時也說明氣相沉積法合成中孔洞-鈣鈦礦複合材料應用於光催化二氧化碳可行性。In this study, the chemical vapor deposition method is used to combine mesopores and carbon materials. Under high temperature reaction (700-900°C) and different reaction times (10-90 minutes), the perovskite structure with air and water vapor sensitivity is attached to the mesopores. Materials, and control the growth of CsPbBr3/Cs4PbBr6 heterostructures, and study the effects of air and vacuum on the luminescence of heterostructures. In order to avoid side reactions such as perovskite oxidation and hydrolysis caused by the growth outside the pores, this study used high-temperature pyrolysis surfactant or ethylene gas to grow surface carbon materials (2.5-5 mmol/g SiO2), not only the perovskite precursor Efficient deposition, simultaneous growth and protection of perovskite nanoparticles, through powder X-ray diffraction experiments and Scherrer fitting empirical formula to prove that nanoparticles (<2 nm) are coated in composite materials. After the composite material is irradiated with purple light (405 nm), the fluorescence intensity of the original perovskite is extinguished by 18 times, which shows that it has a charge separation effect. In the carbon dioxide reduction (CO2RR) experiment, we use the real-time reaction to detect the generation of hydrogen, methane and carbon monoxide, and optimized the carbon dioxide flow rate (10-50 sccm) on the residual air and reaction time (0-6 hours). Three porous supports (MZNs, Ar-MZNs, MGNs) loaded perovskite materials at different temperatures (700-900°C) for carbon dioxide reduction reaction. Among them, the MGNs produced by ethylene cracking have the best catalytic efficiency under UV light (365 nm), and the production of hydrogen, methane and carbon monoxide increased by 13.3%, 14.7%, and 10.0% compared with the initial value. The experimental results of quenching also illustrate the feasibility of mesoporous-perovskite composite materials synthesized by vapor deposition method for photocatalysis of carbon dioxide.