Study On The Photoelectric Properties Of Non-Thermal Plasma Modified TiO₂ Nanomaterials

Finding optoelectronic materials with excellent solar energy conversion performance is of great significance for the development and utilization of solar energy,an important renewable energy source.Titanium dioxide（TiO₂）has attracted widespread attention from researchers in solar energy applications such as photocatalysis,solar cells,and photothermal conversion due to its stable chemical properties,strong chemical reduction ability,and low cost.TiO₂,as a wide bandgap semiconductor with a bandgap of approximately 3.0-3.2 e V,exhibits good light absorption characteristics only in the ultraviolet region,and the visible and near-infrared light,which occupy the majority of the energy in the solar spectrum,have not been fully utilized.Therefore,expanding the absorption range of TiO₂ light from ultraviolet light to the near-infrared region is a key measure to improve the solar energy conversion efficiency of TiO₂.At present,modification strategies to enhance the solar absorption performance of TiO₂ are usually achieved through complex and cumbersome chemical synthesis processes,which pose environmental pollution issues and accompanying risks,which are not conducive to research and application.Therefore,efficient and environmentally friendly TiO₂ modification methods urgently need to be explored.Non thermal plasma has abundant high-energy electrons and active substances,and its macroscopic temperature is close to room temperature.It can quickly and efficiently dope materials with elements and introduce defects,while also possessing the characteristic of environmental friendliness.It has unique advantages in the field of material modification treatment.Based on this,this article focuses on the complex process and environmental pollution issues in the preparation process of traditional TiO₂ based solar conversion materials.Non thermal plasma technology is used to efficiently and environmentally prepare TiO₂based solar conversion materials with good solar absorption performance.The specific work of this article is as follows:（1）The optical absorption performance of anatase TiO₂ in the visible to near-infrared region is improved.In response to the issue of weak absorption performance of TiO₂ in the visible light near-infrared region,nitrogen doped black TiO₂ materials with good light absorption performance were prepared using only N₂,H₂,and Ar gas plasma treatment.Plasma treatment not only achieved effective nitrogen doping to narrow the band gap,but also introduced a large number of Ti³⁺and oxygen vacancy defects,significantly enhancing the light absorption performance.（2）Ti C_xN_1-x/C-N-TiO₂ heterostructure nanoparticles with excellent light absorption performance in the visible to near-infrared region were prepared.On the basis of plasma assisted nitrogen doping technology,CH₄ was added to the precursor gas,and a plasmonic material Ti C_xN_1-x with localized surface plasmon resonance absorption characteristics was grown in situ on the surface of TiO2 using the high-energy reaction conditions of non-thermal plasma.At the same time,TiO₂ was co doped with carbon and nitrogen,a"plasmonic material/semiconductor"heterostructure was formed.There is a plasma induced interfacial charge transfer transition between Ti C_xN_1-x and C-N-TiO₂,resulting in the LSPR absorption peak of Ti C_xN_1-x dephasing,presenting a wide absorption peak covering the visible to near-infrared region,And under the synergistic effect of band gap reduction caused by carbon nitrogen co doping,It makes the material exhibit excellent solar light absorption performance.（3）A self-doped TiO_2-x single crystal thin film with good light absorption performance in the visible to near-infrared region was prepared.The anatase TiO₂ single crystal thin films were treated with H₂ plasma.The H₂ plasma treatment reduced Ti⁴⁺to Ti³⁺in the TiO₂ lattice,and a large number of oxygen vacancies were generated,which effectively increased the carrier concentration of the films.The high carrier concentration causes LSPR absorption of the sample in the near-infrared region,and the"plasmonic material/semiconductor"heterostructure causes the LSPR absorption peak to dephase,presenting a wide absorption peak covering visible light to near-infrared region,making it have good solar light absorption performance.