本研究利用水熱法成長單晶金紅石二氧化鈦奈米柱陣列，並以溶劑熱法成長銳鈦礦奈米粒子於奈米柱表面上，形成金紅石-銳鈦礦複合結構光觸媒。進一步以光沉積法成長鉑與銅奈米粒子於此二氧化鈦複合光觸媒，探討不同共觸媒對光還原二氧化碳之效能影響。由放射光譜分析得知此金紅石-銳鈦礦複合結構光觸媒具有大量表面缺陷，再結合現象嚴重。但此複合結構光觸媒之CH4 產率較金紅石二氧化鈦奈米柱陣列高出1.5 倍。推測其形成之Z-scheme 結構能有效促進光觸媒之效能。沉積鉑奈米粒子於複合結構光觸媒可進一步增加電子電洞對的分離效率。鉑奈米粒子修飾之複合結構光觸媒於光還原二氧化碳實驗中，最高之H2、CO 及CH4 產率分別為4964、1489 及1226 nmol/g/h。與未修飾之復合結構光觸媒相比，各產物產率皆有明顯提升，其中以H2 產率及選擇率增加幅度最大。沉積銅奈米粒子於鉑奈米粒子修飾之複合光觸媒表面時，可進一步增加電子電洞分離效率，且能明顯提升光還原二氧化碳實驗之CH4 與CO 選擇率。光沉積照光時間30 分鐘，前驅物濃度為10-5M 為參數所沉積之銅奈米粒子於複合光觸媒，其最高之CH4 選擇率為78.3 %，但會降低整體光觸媒效能。

A heterojunction nanorod array composed of anatase nanoparticles (ANP) on the surface of the rutile NR (RNR) array were synthesized and further decorated by Pt and Cu nanoparticles (NP). The hybrid photocatalyst was employed to CO2 photoreduction experiment under continuous flow system with GC online detection of H2, CO and CH4. The characterization shows that ANP were deposited on the RNR surface with thickness ~2 nm. Photodeposition Pt onto ANP/RNR resulted in well-deposited Pt NP (3-5 nm). In the CO2 photoreduction experiments, RNR shows mainly CO production while low yield of CH4. After deposited ANP onto RNR, the yield of all gases increase without changing the selectivity. Decorating Pt NPs on the ANP/RNR shows maximum H2, CO and CH4 yield 4964, 1489 and 1226 nmol/g/h, respectively. Further decorating Cu NPs on the Pt/ANP/RNR indicates maximum CH4 selectivity 78.3 %.

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