中孔洞沸石奈米粒子之鋰修飾以及石墨化之合成、鑑定及應用

Abstract

本實驗室研發之自組裝合成法，可生成具有中孔及微孔洞結構的沸石奈米粒子。其高比表面積（800－900 m2/g）、規則中孔洞（5－6 nm）、高結晶性所產生之微孔的性質（< 1 nm），可有效提高其水熱穩定性，並應用於空間限制的載體以及催化等用途。透過有機鋰試劑修飾過程，可使奈米粒子具有捕捉二氧化碳的能力，所產生的碳酸鋰被有效限制於在中孔洞內，並達到循環利用的效果。 透過一步驟的化學氣相沉積反應，並以乙烯氣體做為碳源、直接裂解於沸石表面上，生成單層及數層之氧化石墨烯並維持原中孔洞形貌。經由拉曼光譜、X光光電子能譜、螢光光譜、紫外光－可見光吸收光譜、X光粉末繞射等鑑定，證實其組成結構為中孔洞氧化石墨烯－沸石複合奈米粒子。改質後的奈米粒子，表面可大量吸附有機染料及金屬離子，氧化石墨烯中的自由基並可誘發類芬頓反應，以有效催化有機物之分解。Self-assembly synthesis of mesoporous zeolite nanoparticles (MZNs) with high surface area (800-900 m2/g), uniform mesopores (5-6 nm), and crystalline-induced micropores (<1 nm) have been developed for enhanced hydrothermal stability as well as space-confinement substrates toward adsorption and catalysis purposes. Adsorption applications can be conducted by surface-modified MZNs with organolithium reagents. The captured CO2 results in Li2CO3 products, spatially-confined in the mesopores for recycling and reusing purposes. Mesoporous graphene-oxide zeolite nanoparticles (MGNs) are synthesized via one-step chemical vapor deposition (CVD) method. Ethylene, the onlycarbon source, was decomposed at high temperature and then deposited onto MZNs, forming single and few-layer graphene oxide with retention of original mesoporosity. The evidence of graphene oxide layers is revealed by photoluminescence, UV-Vis absorption, Raman, XPS and XRD spectroscopies. Efficient adsorption of R6G and metal ions was due to the high surface area and the graphene-oxide properties in MGNs. The free radicals in MGNs also induce Fenton-like reaction that decomposes organic compounds for catalysis purposes.