Improved photocatalytic activity of TiO2 nanoparticles through nitrogen and phosphorus co-doped carbon quantum dots: an experimental and theoretical study.
Improved photocatalytic activity of TiO2 nanoparticles through nitrogen and phosphorus co-doped carbon quantum dots: an experimental and theoretical study.
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通过氮磷共掺杂碳量子点提高 TiO2 纳米粒子的光催化活性：实验和理论研究。
DOI：
10.1039/d2cp01405j
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发表时间：
2022
期刊：
影响因子：
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通讯作者：
Yashwanth HJ
中科院分区：
文献类型：
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作者：
Yashwanth HJ
在这项工作中，我们开发了一种光催化剂，其中氮和磷共掺杂的碳量子点支架到二氧化钛纳米粒子（NPCQD/TiO 2），表示为NPCT以下。与氮掺杂CQD/TiO 2（478 μmol h − 1 g − 1）、磷掺杂CQD/TiO 2（451 μmol h−1 g− 1）和纯CQD/TiO 2（427 μmol h− 1 g −1）光催化剂相比，所开发的NPCT光催化剂表现出增强的可见光光催化制氢（533 μmol h−1 g−1）。NPCT光催化剂的增强的光催化活性归因于NPCQD和TiO 2纳米颗粒之间的优异协同作用，这导致虚能级的产生、功函数的降低和复合速率的抑制，从而增加了光生电子的寿命。从实验结果、Mott-Schottky曲线和紫外光电子能谱的结果中提出了NPCT光催化剂增强可见光制氢的详细机理。此外，第一性原理密度泛函理论（DFT）模拟进行预测的功函数和带隙的减少，并在NPCT的状态密度的增加的因素，负责观察到的可见光光催化制氢增强。
In this work, we develop a photocatalyst wherein nitrogen and phosphorus co-doped carbon quantum dots are scaffolded onto TiO2 nanoparticles (NPCQD/TiO2), denoted as NPCT hereafter. The developed NPCT photocatalyst exhibits an enhanced visible light photocatalytic hydrogen production of 533 μmol h−1 g−1 compared to nitrogen doped CQD/TiO2 (478 μmol h−1 g−1), phosphorus doped CQD/TiO2 (451 μmol h−1 g−1) and pure CQD/TiO2 (427 μmol h−1 g−1) photocatalysts. The enhanced photocatalytic activity of the NPCT photocatalyst is attributed to the excellent synergy between NPCQDs and TiO2 nanoparticles, which results in the creation of virtual energy levels, a decrease in work function and suppressed recombination rates, thereby increasing the lifetime of photogenerated electrons. A detailed mechanism is proposed for the enhancement in visible light hydrogen production by the NPCT photocatalyst from the experimental results, Mott–Schottky plots and ultraviolet photoelectron spectroscopy results. Further, first-principles density functional theory (DFT) simulations are carried out which predict the decrease in the work function and band gap, and the increase in the density of states of NPCT as the factors responsible for the observed enhancement in visible light photocatalytic hydrogen production.