Enhancing Light Absorption and Charge Transfer Efficiency in Carbon Dots through Graphitization and Core Nitrogen Doping
Enhancing Light Absorption and Charge Transfer Efficiency in Carbon Dots through Graphitization and Core Nitrogen Doping
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DOI：
10.1002/anie.201700949
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发表时间：
2017-06-01
影响因子：
16.6
通讯作者：
Reisner, Erwin
中科院分区：
文献类型：
--
作者：
Martindale, Benjamin C. M.;Hutton, Georgina A. M.;Reisner, Erwin
单源前体合成已经被设计用于制备结构相似的石墨碳量子点（CD），具有（g-N-CD）和不具有（g-CD）核氮掺杂用于人工光合作用。与未掺杂的CD相比，使用g-N-CD（7950 μ mol（H2）（g（CD））（-1）h（-1））的太阳能（AM 1.5G）H-2释放速率已经实现了一个数量级的改善。所有石墨化的CD显示出显着增强的光吸收相比，非晶CD（α-CD），但未掺杂的g-CD显示有限的光敏剂能力，由于光生电荷的低提取。瞬态吸收光谱表明，在g-N-CD中的氮掺杂增加了电子供体的空穴清除效率，从而显着延长了光生电子的寿命。因此，氮掺杂允许石墨CD的高吸收系数被转化为高电荷提取以用于有效的吸收。
Single-source precursor syntheses have been devised for the preparation of structurally similar graphitic carbon dots (CDs), with (g-N-CD) and without (g-CD) core nitrogen doping for artificial photosynthesis. An order of magnitude improvement has been realized in the rate of solar (AM1.5G) H-2 evolution using g-N-CD (7950 mu mol(H2) (g(CD))(-1) h(-1)) compared to undoped CDs. All graphitized CDs show significantly enhanced light absorption compared to amorphous CDs (a-CD) yet undoped g-CD display limited photosensitizer ability due to low extraction of photogenerated charges. Transient absorption spectroscopy showed that nitrogen doping in g-N-CD increases the efficiency of hole scavenging by the electron donor and thereby significantly extends the lifetime of the photogenerated electrons. Thus, nitrogen doping allows the high absorption coefficient of graphitic CDs to be translated into high charge extraction for efficient photocatalysis.