Mitchell Emma, Law Abigail, Godin Robert
Department of Chemistry, The University of British Columbia, 3247 University Way, Kelowna, BC, V1V 1V7, Canada.
Chem Commun (Camb). 2021 Feb 14;57(13):1550-1567. doi: 10.1039/d0cc06841a. Epub 2021 Jan 25.
Carbon nitride (CN) is an emerging photocatalyst with the potential to efficiently produce solar fuels. CN heterojunctions often show significant photocatalytic activity improvements. We review the charge carrier dynamics in a range of CN heterojunctions including carbon-based material, black phosphorus, Ru complexes, molybdenum sulphide and metal phosphides. Time resolved photoluminescence (TRPL) and transient absorption spectroscopy (TAS) were the most common techniques employed for experimental charge carrier dynamics measurements. The low photoluminescence quantum yield of CN appeared to limit the depth of conclusions from TRPL, with both lengthening and shortening of the TRPL lifetimes observed and attributed to enhanced charge separation. Overall, the charge carrier dynamics studies often showed a relative lifetime change of ∼2-fold and an activity improvement of >10-fold. We highlight the need for the use of a wider range of techniques to monitor the charge carrier dynamics for conclusive determination of photophysics-activity relationships and elucidation of improvement mechanisms.
氮化碳（CN）是一种新兴的光催化剂，具有高效生产太阳能燃料的潜力。CN异质结通常表现出显著的光催化活性提升。我们综述了一系列CN异质结中的电荷载流子动力学，包括碳基材料、黑磷、钌配合物、硫化钼和金属磷化物。时间分辨光致发光（TRPL）和瞬态吸收光谱（TAS）是用于实验测量电荷载流子动力学的最常用技术。CN的低光致发光量子产率似乎限制了TRPL得出结论的深度，观察到TRPL寿命既有延长也有缩短，并归因于电荷分离增强。总体而言，电荷载流子动力学研究通常显示相对寿命变化约为2倍，活性提升超过10倍。我们强调需要使用更广泛的技术来监测电荷载流子动力学，以便最终确定光物理-活性关系并阐明改善机制。
