二維材料在能源上的應用

Abstract

本論文的目的是利用二維材料如石墨烯及硫化鉬的新穎物理和化學性質將其應用在太陽能電池或產氫等能源上。首先導入氬氣、氫氣和甲烷於高溫下利用常壓化學氣相沉積法成長大面積石墨烯於銅箔上，再藉由p型小分子四氰基对苯醌二甲烷(TCNQ)修飾於石墨烯上，經由三層石墨烯與二層TCNQ之堆疊形成較低電阻的電極，以P3HT與PCBM為主動層製備成元件，其元件效率約2.58%;同樣地在發泡鎳上亦可藉由常壓氣相沉積法成長單層或多層之石墨烯，石墨烯可以保護發泡鎳並提升在酸溶液中的穩定性，而石墨烯覆蓋之發泡鎳聚又有高導電、低成本與高表面積的特性，硫化鉬以此為基材有利於S22- 或S2-的活性增加使產氫效率增加；硫化鉬是一個便宜且有前景的產氫材料，藉由導入不同百分比之五氯化鈮可優化硫化鉬之產氫效率，令人驚訝的是只加入1wt%的五氯化鈮便可增加一倍的交換電流密度及得到較低的塔伏斜率。

The objective of this thesis is developing 2D material such as graphene and molybdenum sulfide in solar cell or hydrogen production energy application. Large-area graphene films were synthesized on copper foil by atmospheric chemical vapor deposition using argon, hydrogen and methane. Layer-by-layer molecular doping process on graphene formed sandwiched graphene/tetracyanoquinodimethane (TCNQ)/graphene stacked films for polymer solar cell anodes, where the TCNQmolecules (as p-dopants) were securely embedded between two graphene layers. The P3HT/PCBM device with an anode structure composed of two TCNQ layers sandwiched by three CVD grapheme layers shows optimum PCE (∼2.58%); Large-area graphene films were also synthesized on nickel foam by atmospheric chemical vapor deposition using argon, hydrogen and methane. The graphene films provide robust protection and efficiently increase stability of the nickel foam in acid. This artificial structure is conductive, low cost, with high surface area, and it is ideal to be used as a template to host MoSx catalysts for increasing the number of reaction sites.MoSx catalytic species were likely related to the bridging S22- or apical S2- for electrocatalytic hydrogen evolution reaction (HER); MoSx materials have been considered as cheap and promising catalysts for HER. The addition of NbCl5 in the precursor solution is able to enhance the HER efficiency of obtained MoSx catalysts. Noticeably, the inclusion of only 1 wt% NbCl5 in the MoSx catalysts results in a 100% iii enhancement in exchange current density and a lowering of the Tafel slope to 46 mV/dec.