Qiyi Gan,Huakang Yang,Zining Zhang,Jun Liu,Yudong Guo,Dongxiang Luo,Xiao Liu
In lignin valorization systems, CdSe@CdS nanorods exhibit exceptional photocatalytic performance, where precise control over the rates of oxidation and reduction reactions is crucial. This study introduces a ligand modulation strategy that involves the incorporation of mercaptopropionic acid (MPA) and hexafluorophosphate (PF₆⁻) onto the surface of the nanorods to achieve a balanced redox reaction profile. The inorganic PF₆⁻ ligand primarily promotes reduction reactions, whereas MPA enhances hole transfer. By optimizing the distribution ratio of these ligands, the study achieved a significant enhancement in photocatalytic efficiency, resulting in a 94 % conversion rate for 2-phenoxy-1-phenylethanol (PP-ol) and yields of 67 % and 66 % for phenol and acetophenone, respectively. The distinct roles of MPA and PF₆⁻ can be attributed to their respective spatial site resistances, electrostatic interactions, and surface passivation characteristics. MPA, with its larger spatial resistance, stabilizes and extends hole lifetimes, thereby enhancing hole transfer efficiency. In contrast, PF₆⁻ exhibits lower spatial resistance and stronger electrostatic effects, which facilitate accelerated electron transfer. Furthermore, the ligands optimize the transport pathways for both electrons and holes on the nanorod surface through passivation. This ligand design strategy provides valuable insights for the development of efficient nanorod photocatalysts aimed at biomass valorization.
Ziheng Wang,Xueying Chu,Jinhua Li,Zhankun Weng,Mingze Xu,Yingjiao Zhai,Li Ma,Xiaojun Wang
The polarization-sensitive optical properties of semiconductor nanorods (NRs) are attractive characteristics for optical devices . Although oriented NR films can provide convenient integration and new application opportunities, the realization of large-area NR films with polarized photoluminescence (PL) remains a challenge. Herein, we fabricated ordered CdSe/CdS NR films on an arbitrary substrate using the Langmuir-Blodgett technology. Polarization-sensitive PL was observed for the NR films. The band-edge exciton fine structure owing to the rod-like morphology and the dielectric effect of the orderly arranged NRs were discussed with a focus on the contribution to polarized photons. The degree of linear polarization of the CdSe/CdS NR films excited a circularly polarized light was approximately 0.30. When linearly polarized ultraviolet (UV) light was used as the excitation source, the PL intensity of the NR films periodically varied with the polarization direction of the UV light. The corresponding PL polarization (i.e., “excitation polarization”) was approximately 0.28. The polarization-sensitive fluorescence (approximately 526 nm) excited by the UV-polarized light (325 nm) demonstrates the potential for realizing low-cost polarization-sensitive devices using only a visible light charge-coupled device system.