摘要
本研究成功地開發於FTO基板上成長直立片狀二硫化錫陣列之製程，並研究其光催化二氧化碳轉換之活性。首先，利用旋轉塗佈法製備二氧化錫種子層於FTO基板表面，繼以溶劑熱法於其上成長直立狀二硫化錫二維奈米陣列。經由XRD以及TEM得知，4小時成長的直立二硫化錫二維陣列(4h-V-SnS2)的結晶性較1小時成長者(1h-V-SnS2)佳。而以1h-V-SnS2與4h-V-SnS2為光觸媒催化二氧化碳轉換時，得到乙醛產量分別為88.4 mol/gcat與72.1 mol/gcat。推測原因為結晶性較差之1h-V-SnS2，可能有更多的活性點暴露，進而吸附更多二氧化碳以進行光催化反應。進一步將直立片狀二硫化錫奈米陣列，分別在惰性及硫氣氛下熱處理(Ar-1h-V-SnS2與S-1h-V-SnS2)，改變樣品的表面狀態與結晶性，討論其對於二氧化碳光轉換效能的影響。以Ar-1h-V-SnS2與S-1h-V-SnS2進行光催化二氧化碳轉換反應時，可以得到乙醛產量分別為110 mol/gcat與82.6 mol/gcat。在Ar環境下熱處理，會使1h-V-SnS2結晶性提升，但同時形成Sn2S3相。結晶性提升可降低載子於光觸媒內之遷移障礙，而存在之缺硫相態，可能成為光催化之活性點，或是增進二氧化碳的吸附，進而增進光轉換的效能。
關鍵字: 二硫化錫、二維奈米結構、光觸媒、直立成長陣列、二氧化碳光轉換、表面缺陷、結晶性

In this work, vertically aligned SnS2 arrays have been successfully synthesized on SnO2 seeded FTO substrates by the solvothermal process. The SnS2 photocatalysts was employed to CO2 photoconversion experiment under batch reactor filled with CO2 (99.9999 %) with GC detectors to detect hydrocarbon components. The Ar-treated 1h-V-SnS2(Ar-1h-V-SnS2) photocatalyst shows photocatalytic CO2 conversion to acetaldehyde with the highest yield about 11 mol gat-1 h-1 compared to those of 1h-V-SnS2(8.84 mol gat-1 h-1) and Sulfur-vapor treated 1h-V-SnS2(8.26 mol gat-1 h-1). From the XRD and HR-TEM characterizations results, it showed the vacancy of sulfur in Ar-1h-V-SnS2, and we suggested that it might help the CO2 adsorption on the surface of SnS2 photocatalysts.

Key words: tin disulfide, 2D-nanostructure, photocatalyst, vertical aligned array, CO2 photoconversion, surface defect, crystallinity

參考文獻
[1] Zhang, L., Zhao, Z. J., and Gong, Nanostructured materials for heterogeneous electrocatalytic CO2 reduction and their related reaction mechanisms. Angewandte Chemie International Edition, 2017, 56(38): 11326-11353.
[2] Schreck, M., and Niederberger, M., Photocatalytic Gas Phase Reactions. Chemistry of Materials, 2019, 31(3): 597-618.
[3] Yang, X., and Wang, D., Photocatalysis: from fundamental principles to materials and applications. ACS Applied Energy Materials, 2018, 1(12): 6657-6693.
[4] Nahar, S., Zain, M., Kadhum, A., Hasan, H., and Hasan, M., Advances in photocatalytic CO2 reduction with water: a review. Materials, 2017, 10(6): 629.
[5] Sun, Z., Talreja, N., Tao, H, Texter, J., Muhler, M., Strunk, J., and Chen, J., Catalysis of carbon dioxide photoreduction on nanosheets: fundamentals and challenges. Angewandte Chemie International Edition, 2018, 57(26): 7610-7627.
[6] Alfaifi, B. Y., Ullah, H., Alfaifi, S., Tahir, A. A., and Mallick, T. K., Photoelectrochemical solar water splitting: From basic principles to advanced devices. Veruscript Funct. Nanomater, 2018, 2, 1-26.
[7] Xiao, M., Wang, Z., Luo, B., Wang, S., and Wang, L., Enhancing photocatalytic activity of tantalum nitride by rational suppression of bulk, interface and surface charge recombination. Applied Catalysis B: Environmental, 2019, 246: 195-201.
[8] Li, K., Peng, B., and Peng, T., Tianyou. Recent advances in heterogeneous photocatalytic CO2 conversion to solar fuels. ACS Catalysis, 2016, 6(11): 7485-7527.
[9] Low, J., Cheng, B., and Yu, J., Surface modification and enhanced photocatalytic CO2 reduction performance of TiO2: a review. Applied Surface Science, 2017, 392: 658-686.
[10] Zhang, G., Chen, D., Li, N., Xu, Q., Li, H., He, J., and Lu, J., SnS2/SnO2 heterostructured nanosheet arrays grown on carbon cloth for efficient photocatalytic reduction of Cr (VI). Journal of colloid and interface science, 2018, 514: 306-315.
[11] Sun, Y., Cheng, H., Gao, S., Sun, Z., Liu, Q., and Xie, Y., Freestanding tin disulfide single‐layers realizing efficient visible‐light water splitting. Angewandte Chemie International Edition, 2012, 51(35): 8727-8731.
[12] Shown, I., Samireddi, S., Chang, Y. C., Putikam, R., Chang, P. H., Sabbah, A., ... and Chung, P. W., Carbon-doped SnS2 nanostructure as a high-efficiency solar fuel catalyst under visible light. Nature communications, 2018, 9(1): 169.
[13] Burton, L. A., Colombara, D., Abellon, R. D., Grozema, F. C., Peter, L. M., Savenije, T. J., ... and Walsh, A., Synthesis, characterization, and electronic structure of single-crystal SnS, Sn2S3, and SnS2. Chemistry of Materials, 2013, 25(24): 4908-4916.
[14] Wang, F., Shifa, T. A., Zhan, X., Huang, Y., Liu, K., Cheng, Z., ... and He, J., Recent advances in transition-metal dichalcogenide based nanomaterials for water splitting. Nanoscale, 2015, 7(47): 19764-19788.
[15] Yu, J., Xu, C. Y., Ma, F. X., Hu, S. P., Zhang, Y. W., and Zhen, L., Monodisperse SnS2 nanosheets for high-performance photocatalytic hydrogen generation. ACS applied materials & interfaces, 2014, 6(24): 22370-22377.
[16] Jing, L., Xu, Y., Chen, Z., He, M., Xie, M., Liu, J., ... and Li, H., Different morphologies of SnS2 supported on 2D g-C3N4 for excellent and stable visible light photocatalytic hydrogen generation. ACS Sustainable Chemistry & Engineering, 2018, 6(4): 5132-5141.
[17] Liu, E., Chen, J., Ma, Y., Feng, J., Jia, J., Fan, J., and Hu, X., Fabrication of 2D SnS2/g-C3N4 heterojunction with enhanced H2 evolution during photocatalytic water splitting. Journal of colloid and interface science, 2018, 524: 313-324.
[18] Sun, Y., Li, G., Xu, J., and Sun, Z., Visible-light photocatalytic reduction of carbon dioxide over SnS2. Materials Letters, 2016, 174: 238-241.
[19] Zhang, A., He, R., Li, H., Chen, Y., Kong, T., Li, K., ... and Zeng, J., Nickel Doping in Atomically Thin Tin Disulfide Nanosheets Enables Highly Efficient CO2 Reduction. Angewandte Chemie International Edition, 2018, 57(34): 10954-10958.
[20] Jiao, X., Li, X., Jin, X., Sun, Y., Xu, J., Liang, L., ... and Lin, Y., Partially oxidized SnS2 atomic layers achieving efficient visible-light-driven CO2 reduction. Journal of the American Chemical Society, 2017, 139(49): 18044-18051.
[21] Xiong, J., Di, J., Xia, J., Zhu, W., and Li, H., Surface defect engineering in 2D nanomaterials for photocatalysis. Advanced Functional Materials, 2018, 28(39): 1801983.
[22] Liu, G., Li, Z., Hasan, T., Chen, X., Zheng, W., Feng, W., ... & Hu, P., Vertically aligned two-dimensional SnS2 nanosheets with a strong photon capturing capability for efficient photoelectrochemical water splitting. Journal of Materials Chemistry A, 2017, 5(5): 1989-1995.
[23] Liu, G., Li, Z., Hasan, T., Chen, X., Zheng, W., Feng, W., ... and Hu, P., Status and perspectives of CO2 conversion into fuels and chemicals by catalytic, photocatalytic and electrocatalytic processes. Energy & environmental science, 2013, 6(11): 3112-3135.
[24] Dilla, M., Schlögl, R., and Strunk, J., Photocatalytic CO2 Reduction Under Continuous Flow High‐Purity Conditions: Quantitative Evaluation of CH4 Formation in the Steady‐State. ChemCatChem, 2017, 9(4): 696-704.
[25] Duan, Z., and Sun, R., An improved model calculating CO2 solubility in pure water and aqueous NaCl solutions from 273 to 533 K and from 0 to 2000 bar. Chemical geology, 2003, 193(3-4): 257-271.
[26] Ma, Y., Wang, X., Jia, Y., Chen, X., Han, H., and Li, C., Titanium dioxide-based nanomaterials for photocatalytic fuel generations. Chemical reviews, 2014, 114(19): 9987-10043.
[27] Cheng, B. Y., Yang, J. S., Cho, H. W., and Wu, J. J., Fabrication of an efficient BiVO4–TiO2 heterojunction photoanode for photoelectrochemical water oxidation. ACS applied materials & interfaces, 2016, 8(31): 20032-20039.
[28] Yang, J. S., Liao, W. P., and Wu, J. J., Morphology and interfacial energetics controls for hierarchical anatase/rutile TiO2 nanostructured array for efficient photoelectrochemical water splitting. ACS applied materials & interfaces, 2013, 5(15): 7425-7431.
[29] ahir, M., Tahir, B., Amin, N. A. S., and Alias, H., Selective photocatalytic reduction of CO2 by H2O/H2 to CH4 and CH3OH over Cu-promoted In2O3/TiO2 nanocatalyst. Applied Surface Science, 2016, 389: 46-55.
[30] Pan, B., Luo, S., Su, W., and Wang, X., Photocatalytic CO2 reduction with H2O over LaPO4 nanorods deposited with Pt cocatalyst. Applied Catalysis B: Environmental, 2015, 168: 458-464.
[31] Dong, C., Lian, C., Hu, S., Deng, Z., Gong, J., Li, M., ... and Zhang, J., Size-dependent activity and selectivity of carbon dioxide photocatalytic reduction over platinum nanoparticles. Nature communications, 2018, 9(1): 1252.
[32] Im, H. S., Myung, Y., Cho, Y. J., Kim, C. H., Kim, H. S., Back, S. H., ... and Ahn, J. P., Facile phase and composition tuned synthesis of tin chalcogenide nanocrystals. RSC Advances, 2013, 3(26): 10349-10354.
[33] Ma, J., Lei, D., Mei, L., Duan, X., Li, Q., Wang, T., and Zheng, W., Plate-like SnS2 nanostructures: Hydrothermal preparation, growth mechanism and excellent electrochemical properties. CrystEngComm, 2012, 14(3): 832-836.
[34] Doyle, T. E., and Dennison, J. R., Vibrational dynamics and structure of graphitic amorphous carbon modeled using an embedded-ring approach. Physical Review B, 1995, 51(1): 196.
[35] Nakashima, S., Katahama, H., and Mitsuishi, A., The effect of polytypism on the vibrational properties of SnS2. Physica B+ C, 1981, 105(1-3): 343-346.
[36] Wang, J. G., Sun, H., Liu, H., Jin, D., Zhou, R., and Wei, B., Edge-oriented SnS2 nanosheet arrays on carbon paper as advanced binder-free anodes for Li-ion and Na-ion batteries. Journal of Materials Chemistry A, 2017, 5(44): 23115-23122.
[37] Jiang, Y., Wei, M., Feng, J., Ma, Y., and Xiong, S., Enhancing the cycling stability of Na-ion batteries by bonding SnS2 ultrafine nanocrystals on amino-functionalized graphene hybrid nanosheets. Energy & Environmental Science, 2016, 9.(4): 1430-1438.
[38] Chia, X., Lazar, P., Sofer, Z., Luxa, J., and Pumera, M., Layered SnS versus SnS2: valence and structural implications on electrochemistry and clean energy electrocatalysis. The Journal of Physical Chemistry C, 2016, 120(42): 24098-24111.
[39] Zhang, F., Lian, Y., Gu, M., Yu, J., & Tang, T. B., Static and Dynamic Disorder in Metastable Phases of Tin Oxide. The Journal of Physical Chemistry C, 2017, 121(29): 16006-16011.
[40] Razzaq, A. A., Yao, Y., Shah, R., Qi, P., Miao, L., Chen, M., ... and Deng, Z., High-performance lithium sulfur batteries enabled by a synergy between sulfur and carbon nanotubes. Energy Storage Materials, 2019, 16: 194-202.
[41] Ye, J., He, F., Nie, J., Cao, Y., Yang, H., and Ai, X., Sulfur/carbon nanocomposite-filled polyacrylonitrile nanofibers as a long life and high capacity cathode for lithium–sulfur batteries. Journal of Materials Chemistry A, 2015, 3(14): 7406-7412.
[42] Wang, C., Tang, K., Yang, Q., and Qian, Y., Raman scattering, far infrared spectrum and photoluminescence of SnS2 nanocrystallites. Chemical physics letters, 2002, 357(5-6): 371-375.
[43] Rauf, A., Shah, M. S. A. S., Lee, J. Y., Chung, C. H., Bae, J. W., and Yoo, P. J., Non-stoichiometric SnS microspheres with highly enhanced photoreduction efficiency for Cr (VI) ions. RSC Advances, 2017, 7(49): 30533-30541.
[44] Lupoi, J. S., Gjersing, E., and Davis, M. F., Evaluating lignocellulosic biomass, its derivatives, and downstream products with Raman spectroscopy. Frontiers in bioengineering and biotechnology, 2015, 3: 50.