Meng Xiangtong, Yu Chang, Song Xuedan, Iocozzia James, Hong Jiafu, Rager Matthew, Jin Huile, Wang Shun, Huang Longlong, Qiu Jieshan, Lin Zhiqun
State Key Lab of Fine Chemicals, School of Chemical Engineering, Liaoning Key Lab for Energy Materials and Chemical Engineering, Dalian University of Technology, Dalian, 116024, Liaoning, P. R. China.
School of Materials Science and Engineering, Georgia Institute of Technology, Atlanta, GA, 30332, USA.
Angew Chem Int Ed Engl. 2018 Apr 16;57(17):4682-4686. doi: 10.1002/anie.201801337. Epub 2018 Mar 15.
Understanding the impact of the defects/defect density of electrocatalysts on the activity in the triiodide (I ) reduction reaction of dye-sensitized solar cells (DSSCs) is indispensable for the design and construction of high-efficiency counter electrodes (CEs). Active-site-enriched selenium-doped graphene (SeG) was crafted by ball-milling followed by high-temperature annealing to yield abundant edge sites and fully activated basal planes. The density of defects within SeG can be tuned by adjusting the annealing temperature. The sample synthesized at an annealing temperature of 900 °C exhibited a superior response to the I reduction with a high conversion efficiency of 8.42 %, outperforming the Pt reference (7.88 %). Improved stability is also observed. DFT calculations showed the high catalytic activity of SeG over pure graphene is a result of the reduced ionization energy owing to incorporation of Se species, facilitating electron transfer at the electrode-electrolyte interface.
了解电催化剂的缺陷/缺陷密度对染料敏化太阳能电池（DSSC）中碘化物（I）还原反应活性的影响，对于高效对电极（CE）的设计和构建至关重要。通过球磨然后高温退火制备了富含活性位点的硒掺杂石墨烯（SeG），以产生大量边缘位点并充分激活基面。SeG中的缺陷密度可以通过调节退火温度来调整。在900°C退火温度下合成的样品对I还原表现出优异的响应，具有8.42%的高转换效率，优于Pt参比（7.88%）。还观察到稳定性有所提高。密度泛函理论计算表明，SeG比纯石墨烯具有更高的催化活性是由于掺入Se物种导致电离能降低，促进了电极-电解质界面处的电子转移。
