基于分层Ti3C2 MXene纳米片的多巴胺电化学检测

选择多巴胺作为标志物，构建了基于分层Ti₃C₂ MXene(DL-Ti₃C₂)纳米片的电化学检测平台。通过原位锂离子插层法成功合成了DL-Ti₃C₂纳米片。采用扫描电镜和X-射线粉末衍射等手段对Ti₃C₂ MXene纳米片进行了微观形貌及结构表征。利用循环伏安法研究了多巴胺的电化学行为，结果表明DL-Ti₃C₂纳米片比多层Ti₃C₂ Mxene(ML-Ti₃C₂)纳米片具有更优异的电化学分析性能。基于DL-Ti₃C₂纳米片独特的二维纳米片形态、大的比表面积和优异的导电率，所制备的传感器能够实现对多巴胺的高灵敏检测，检出限为0.33μmol/L。该传感平台可用于针对飞行员的特殊神经精神性疾病检测。     

制备条件对MXene形貌、 结构与电化学性能的影响

以Ti₃AlC₂为原料, 采用LiF+HCl一步刻蚀-插层制备Ti₃C₂T_x, 进一步通过超声处理得到单层或少层的MXene. 利用X射线衍射(XRD)、 X射线光电子能谱(XPS)、 扫描电子显微镜(SEM)、 透射电子显微镜(TEM)和电化学测试对样品的结构、 形貌和电化学性能进行了研究. 通过改变刻蚀剂的比例及超声剥离时间, 研究了不同刻蚀条件和剥离条件对二维晶体Ti₃C₂T_x的形貌、 结构和电化学性能的影响. 结果表明, 制备条件对MXene的片层结构和性能具有较大的影响. 当HCl浓度为6 mol/L, LiF与Ti₃AlC₂的摩尔比为7.5, 超声时间为1 h时, 所得MXene具有较小的晶格常数和较大的片层尺寸, 片层尺寸可达1 μm, 具有较多的表面含氧官能团, 电化学性能最佳, 在0.5 A/g的电流密度下, 质量比容量达到342 F/g, 当电流密度提高至20 A/g时, 质量比容量仍可保持244 F/g, 在1 A/g电流密度下循环10000周后, 容量仍能保留87%左右, 表现出较好的倍率性能与循环稳定性.     

二维Ti2C与Ti3C2表面OH、O、F、Au的吸附活性

较高的比表面积与稳定性使得二维Ti₂C与Ti₃C₂结构在贵金属催化剂载体、锂离子电池、储氢材料等领域具有重要的应用前景. 研究Ti₂C、Ti₃C₂的表面吸附活性有助于认识其表面特征. 第一性原理计算研究显示:Ti₂C与Ti₃C₂对O、OH、F具有较强的吸附活性. 通过比较Ti₂C、Ti₃C₂、Ti(001)、TiC(001)的表面电子结构, 我们发现Ti₂C与Ti₃C₂较强的表面吸附活性来自于表面Ti 原子未极化的3d轨道. 这使得Ti₂C、Ti₃C₂表面通常覆盖有O、F、OH. 吸附了O、OH基团的Ti₂C与Ti₃C₂结构(Ti₂CO_2-2x(OH)_2x、Ti₃C₂O_2-2x(OH)_2x)对Au原子的吸附能随OH比例的增大而增大.     

具有水下超疏油性能的MXene高效油水分离膜

基于二维材料MXene(Ti₃C₂T_x)的化学组成和纳米片状结构, 在不锈钢网上制备了具有MXene微纳结构表面的新型亲水和水下超疏油分离膜. 对于不同类型的油-水混合物, 该膜材料可实现重力驱动的高效油水分离, 收集的水中残油量小于4 mg/L, 具有高分离效率(>99.99%), 水通量高达57.52 L·m^-2·s^-1. 此外, 经高温处理和多种有机溶剂浸泡后MXene膜仍具有高效的油水分离性能, 并表现出优异的稳定性和循环性.     

三维MXene多孔结构的构建与应用研究进展

MXene作为一种新型二维（2D）纳米材料以其独特的高导电性、高电化学表面活性等特性在多个领域引起了广泛关注。然而,MXene纳米片在自组装过程中出现的紧密堆叠现象导致比表面积急剧下降,降低了活性表面积,从而严重阻碍了它们在能源储存、电磁屏蔽、吸附等领域的潜在应用。构建三维多孔结构是解决MXene组装过程中自堆叠问题的一种有效途径,而且通过不同的组装方法可以实现对多孔宏观结构组成成分、孔径分布以及孔径大小的调控,使得MXene多孔材料在机械性能、电学性能以及光热转换性能等方面得到更好的调整,从而满足不同应用领域的需求。本综述以Ti₃C₂T_x MXene为主要研究材料总结了各种多孔MXene宏观结构的制备方法,讨论了其在电池/超级电容器、电磁屏蔽与吸收、海水淡化、光催化以及传感和环境修复等方面的应用,阐述了MXene多孔结构在各种应用中的贡献与意义,并针对MXene多孔结构的制备、结构调控和应用等方面的机遇和挑战作了论述。     

Ti3C2 MXene助催化剂组装的介孔TiO2用以增强光催化甲基橙降解和产氢活性

利用太阳能驱动半导体光催化剂进行光催化降解污染物和产氢被认为是解决环境问题和能源危机最有效的方法之一.在众多的半导体光催化剂中,TiO₂因其优异的化学稳定性、环境友好和成本低等优点,在光催化领域具有不可或缺的作用.介孔TiO₂由于具有独特的介孔结构,更有利于光催化过程中反应物的吸附和传输.然而,单一TiO₂具有较高的光生载流子重组效率和低的光利用率等缺点,导致其光催化活性低.通过负载助催化剂可以增强光吸收、促进光生载流子的分离以及提供更多活性位点,是提高光催化活性的一种有效策略.目前,常用的高效助催化剂主要为贵金属,如Pt,Pd和Au等,但昂贵的价格及稀缺性限制了其在未来的广泛应用.因此,寻找新型的非贵金属助催化剂来提高光催化剂的活性具有重要意义.MXene作为一种新型的二维过渡金属碳化物和/或氮化物,具有丰富的表面亲水性官能团、良好的金属导电性和较高的载流子迁移率等特性,适合用于光催化中作为助催化剂来提高光催化性能.受此启发,本文利用静电自组装策略将介孔TiO₂纳米颗粒均匀地固定在Ti₃C₂MXene助催化剂上,构建了紧密的介孔TiO₂/Ti₃C₂复合材料,并研究其光催化降解甲基橙(MO)和产氢性能.Zeta电位测试结果表明,带有相反表面电荷的介孔TiO₂和Ti₃C₂可以通过静电作用构筑稳定的复合材料.X-射线粉末衍射、拉曼光谱、X-射线光电子能谱(XPS)、透射电子显微镜和高分辨透射电子显微镜等表征也进一步表明,成功制备了介孔TiO₂/Ti₃C₂复合材料.XPS也证明在复合材料中光生电子从TiO₂转移到Ti₃C₂助催化剂上,表明两者之间具有强相互作用.BET测试结果表明,相比单一的介孔TiO₂,复合材料具有更大的比表面积和孔体积,可提供更多的活性位点,有利于提高光催化活性.紫外-可见漫反射光谱表明,Ti₃C₂助催化剂的引入提高了材料的光吸收能力.荧光光谱、时间分辨荧光光谱、光电流密度和电化学阻抗等测试结果表明,复合材料具有优异的光生载流子分离和转移能力.在光催化性能测试中,最佳Ti₃C₂含量(3wt%)的介孔TiO₂/Ti₃C₂复合材料在40 min内对MO的光催化降解效率可达99.6%,并利用自由基捕获实验和电子自旋共振表征证实了活性物种·O₂-和·OH在光催化降解过程中起主要作用.此外,该复合材料也表现出了较好的产氢性能(218.85μmolg^-1h^-1),约为单一介孔TiO₂的5.6倍,且三次循环后仍保持稳定的产氢效率.综上,MXene族材料可以作为一种高效的非贵金属助催化剂应用于光催化领域.     

基于Cu2S电阻开关器件的光电记忆效应

硫化亚铜由于其独特的电和光学特性，被广泛应用于电阻开关存储和光伏器件.本文通过脉冲激光沉积/化学气相沉积两步法合成Cu₂S薄膜，该膜由纳米颗粒构成，结晶度高，在近红外区有较好的光吸收特性.蒸镀铜电极构成Cu/Cu₂S/P-Si结构忆阻器件后，器件表现出电子型双极阻变行为，其阻变机制由空间电荷限制电流和肖特基发射机制协同主导.此外，还探究了光对器件阻变行为的响应及机理.结果表明，在光照下，最大电流响应增加至暗态时的5倍.分析认为，光照使Cu/Cu₂S界面处的肖特基势垒减小，在高阻态下，阻变机制由肖特基发射机制转变为空间电荷限制电流机制，并使器件电导率增加.本工作为Cu₂S基光电协同响应忆阻器的研发提供了新思路.     

基于Ti3C2-MXene的太阳能界面水汽转换

水资源匮乏是现代化发展中面临的全球性问题,太阳能界面水汽转换(Interfacial Solar Steam Generation, ISSG)是一种高效、绿色、低成本进行海水淡化和废水处理的方法。ISSG使用绿色的太阳能作为热源,通过光热转换并将热限制在水气界面上以高效产生蒸气,然后经过冷凝收集获得清洁水。设计和构筑具有强光吸收的光热转换材料是ISSG的技术核心。Ti₃C₂-MXene是一种新型二维碳化钛材料,具有比表面积大、水分散性好和光热转换效率高等优点,在ISSG领域具有巨大的应用潜力。本文介绍了ISSG技术和MXene,总结了光热转换材料的设计原则,论述了Ti₃C₂-MXene复合材料在ISSG领域的研究进展,其中包括二维MXene薄膜、三维MXene气凝胶和水凝胶、生物基-MXene复合材料的构筑和性能等,并分析了Ti₃C₂-MXene所面临的挑战和发展前景。     

Preparation and tribological properties of potassium titanate-Ti3C2Tx nanocomposites as additives in base oil

The potassium titanate-Ti₃C₂T_x nanocomposite was successfully synthesized by a simple one-step chemical process using Ti₃C₂T_x and potassium hydroxide at room temperature. Compare to Ti₃C₂T_x nanosheets, the potassium titanate-Ti₃C₂T_x exhibits superior tribological properties.     

Long-cycling lithium-oxygen batteries enabled by tailoring Li nucleation and deposition via lithiophilic oxygen vacancy in Vo-TiO2/Ti3C2Tx composite anodes

Uncontrollable Li dendrite growth and infinite volume fluctuation during durative plating and stripping process gravely hinder the application of metallic Li electrode in lithium-oxygen batteries.Herein,oxygen vacancy-rich TiO₂(Vo-TiO₂)nanoparticles(NPs)uniformly dispersing on Ti₃C₂T_x(Vo-TiO₂/Ti₃C₂ T_x)with excellent lithiophilicity feature are presented as effective composite anodes,on which a dense and uniform Li growth behavior is observed.Based on electrochemical studies,mutiphysics simulation and theoretical calculation,it is found that Vo-TiO₂ coupling with three dimensional(3 D)conductive Ti₃C₂ T_x MXene forms highly ordered lithiophilic sites which succeed in guiding Li ions flux and adsorption,thus modulating the uniform Li nucleation and growth.As a result,this composite electrode is capable of preserving Li with high areal capacity of~10 mAh cm^-2 without the presence of dendrites and large volume expansion.Consequently,the as-prepared Vo-TiO₂/Ti₃C₂ T_x@Li anode shows outstanding performance including low voltage hysteresis(~19 mV)and superior durability(over 750 h).When assembling with the Vo-TiO₂/Ti₃C₂ T_x@Li anodes,lithium-oxygen batteries also deliver enhanced cycling stability and improved rate performance.This work demonstrates the effectiveness of oxygen vacancies in guiding Li nucleating and plating behavior at initial stage and brings a promising strategy for promoting the development of advanced Li metal-based batteries.     

1D Mn0.2Cd0.8S纳米棒/2D Ti3C2纳米片肖特基异质结的构建及光催化产氢性能研究

Sustainable photocatalytic H₂ evolution has attracted extensive attention in recent years because it can address both energy shortage and environmental pollution issues. In particular, metal sulfide solid-solution photocatalysts have been widely applied in photocatalytic hydrogen generation owing to their excellent light harvesting properties, narrow enough band gap, and suitable redox potentials of conduction and valance bands. However, it is still challenging to develop low-cost and high-efficiency sulfide solid-solution photocatalysts for practical photocatalytic hydrogen evolution. Recently, 1D Mn_xCd_1-xS nanostructures have shown superior light absorption, charge separation, and H₂-evolution activity owing to their shortened diffusion pathway of carriers and high length-to-diameter ratios. Thus, 1D Mn_xCd_1-xS nanostructures have been applied in photocatalytic H₂ evolution. However, a single Mn_xCd_1-xS photocatalyst still has some disadvantages for photocatalytic H₂ evolution, such as the rapid recombination of photogenerated electron-hole pairs and low quantum efficiency. Herein, to further boost the separation of photogenerated charge carriers and H₂-evolution kinetics, an in situ solvothermal method was used to synthesize the 1D/2D Schottky-based heterojunctions between the Mn_0.2Cd_0.8S nanorods (MCS NRs) and Ti₃C₂ MXene nanosheets (NSs). Furthermore, various characterization methods have been used to investigate the crucial roles and underlying mechanisms of metallic Ti₃C₂ MXene NSs in boosting the photocatalytic H₂ evolution over the Mn_0.2Cd_0.8S nanorods. X-ray Diffraction (XRD), Transmission Electron Microscope (TEM), High Resolution Transmission Electron Microscopy (HRTEM), element mapping images, and X-ray Photoelectron Spectroscopy (XPS) results clearly demonstrate that hybrid low-cost Schottky-based heterojunctions have been successfully constructed for practical applications in photocatalytic H₂ evolution. Additionally, the photocatalytic hydrogen evolution reaction (HER) was also carried out in a mixed solution of Na₂SO₃ and Na₂S using as the sacrificial agents. The highest hydrogen evolution rate of the optimized 1D/2D Schottky-based heterojunction is 15.73 mmol·g^-1·h^-1, which is 6.72 times higher than that of pure MCS NRs (2.34 mmol·g^-1·h^-1). An apparent quantum efficiency of 19.6% was achieved at 420 nm. The stability measurements of the binary photocatalysts confirmed their excellent photocatalytic stability for practical applications. More interestingly, the UV-Vis diffuse reflection spectra, photoluminescence (PL) spectrum, transient photocurrent responses, and Electrochemical Impedance Spectroscopy (EIS) Nyquist plots clearly confirmed the promoted charge separation between the MCS NRs and Ti₃C₂ MXene NSs. The linear sweep voltammetry also showed that the loading of MXene cocatalysts could greatly decrease the overpotential of pure MCS NRs, suggesting that the 2D Ti₃C₂ NSs could act as an electronic conductive bridge to improve the H₂-evolution kinetics. In summary, these results show that the 2D/1D hybrid Schottky-based heterojunctions between metallic Ti₃C₂ MXene NSs and MCS NRs can not only improve the separation of photogenerated electrons and holes but also decrease the H₂-evolution overpotential, thus resulting in significantly enhanced photocatalytic H₂ generation. We believe that this study will inspire new ideas for constructing low-cost Schottky-based heterojunctions for practical applications in photocatalytic H₂ evolution.      

基于密度泛函理论下H2S在单原子催化剂V/Ti2CO2上的分解机理研究

In-depth understanding of the mechanisms of hydrogen sulfide (H₂S) adsorption on catalysts during desulfurization from industrial waste gas streams is important for developing effective catalysts to be used in the decomposition of H₂S. In this work, the dissociation behavior of H₂S adsorbed on a single-atom catalyst (Ti or V-decorated Ti₂CO₂ surface) was investigated by performing density functional theory (DFT) calculations. The corresponding diffusion behavior revealed that Ti or V atoms could be dispersed on the Ti₂CO₂ monolayer, without aggregation in the form of single atoms. In addition, analyses of the partial density of states (PDOS), Hirshfeld charges, and electron density difference indicated that the decorated Ti or V atoms led to charge redistribution on the Ti₂CO₂ surface and significantly improved the interaction between the H₂S gas molecules and Ti₂CO₂, thereby enhancing the catalytic activity of V/Ti₂CO₂. In order to gain a deeper understanding of the mechanism of H₂S decomposition (H₂S → HS* + H* → H₂ + S*), a comparative analysis of the results for the decomposition of H₂S on the Ti/Ti₂CO₂ and V/Ti₂CO₂ surfaces was carried out. The catalytic dissociation behavior of H₂S is explained as follows: once H₂S is adsorbed on the V/Ti₂CO₂ or Ti/Ti₂CO₂ surface, it spontaneously dissociates into HS*/H* without any energy barrier on the catalyst surface. Subsequently, the V atoms would not only promote the cleavage of the H-S bond, but also play a major role in the formation of S atoms. Moreover, the rate-limiting step for the entire process proceeded on the Ti/Ti₂CO₂ surface with an energy barrier of 0.86 eV, while that for V/Ti₂CO₂ was 0.28 eV, indicating that the H₂S molecules easily dissociated into S and H₂ on the V/Ti₂CO₂ surface at room temperature. The reaction time for H₂S decomposition on the V/Ti₂CO₂ surface at 500 K was 65.79 ns, which was almost two orders of magnitude higher than that at room temperature. Thus, the decomposition of H₂S on the V-doped Ti₂CO₂ surface is associated very fast kinetics. Furthermore, the S atoms can form elemental sulfur with aggregation on the V/Ti₂CO₂ surface to promote recycling reactions. Compared with previously reported catalytic systems, the single-atom catalyst (SAC) V/Ti₂CO₂ catalyst has greater application prospects in terms of sustainable economy or removal efficiency for H₂S treatment. Our results suggest that V-doped Ti₂CO₂ is an excellent candidate for a highly effective non-noble metal catalyst applicable to H₂S decomposition.      

Bimetallic Sulfide/Sulfur Doped T3C2Tx MXene Nanocomposites as High-performance Anode Materials for Sodium-ion Batteries

The application of transition metal dichalcogenides(TMDs) as anode materials in sodium-ion batteries (SIBs) has been hindered by low conductivity and poor cyclability. Herein, we report the synthesis of Co_xFe_1-xS₂ bimetallic sulfide/sulfur-doped Ti₃C₂ MXene nanocomposites(Co_xFe_1-xS₂@S-Ti₃C₂) by a facile co-precipitation process and thermal-sulfurization reaction. The interconnected 3D frameworks consisting of MXene nanosheets can effectively buffer the volume change and enhance the charge transfer. In particular, sulfur-doped MXene nanosheets provide rich active sites for sodium storage and restrain sulfur loss during charging/discharging processes, leading the increase of specific capacity and cycling the stability of anode materials. As a result, Co_xFe_1-xS₂@S-Ti₃C₂ anodes exhibited high capacity, high rate capability and long cycle life(399 mA·h/g at 5 A/g with an 94% capacity retention after 600 cycles).     

硫掺杂二氧化钛/碳化钛复合材料的制备及储锂性能

通过二维层状Ti_3C_2的原位水热氧化和气相硫化反应,制备了硫掺杂二氧化钛/碳化钛(S-TiO_2/Ti_3C_2)复合材料,并用于电化学储锂。结果表明,二氧化钛纳米颗粒原位生长在碳化钛片层上,且硫成功掺杂到二氧化钛中。这种S-TiO_2/Ti_3C_2复合结构作为锂离子电池的负极材料,表现出较好的电化学性能。在0.2 A/g的电流密度下循环100圈后,放电比容量稳定在288 m A·h/g,远高于纯Ti_3C_2和TiO_2/Ti_3C_2电极的放电比容量。S-TiO_2/Ti_3C_2复合材料表现出的较高比容量和良好的循环性能,主要归因于复合材料的特殊纳米结构优势:二氧化钛原位生长在碳化钛上,使复合材料具有稳定良好的接触界面,能够促进电子的快速转移,同时可以有效避免循环过程中两种组分的分离;硫在二氧化钛中的掺杂可以提高二氧化钛的导电性,并引入缺陷,提高反应活性。此研究工作为二维材料的原位转化及复合提供了新的思路和研究方法。     

反蛋白石结构的g-C3N4可控合成及其优异的光催化产氢性能

The growing frustration from facing energy shortages and unbalanced environmental issues has obstructed the long-term development of human society. Semiconductor-based photocatalysis, such as water splitting, transfers solar energy to storable chemical energy and is widely considered an economic and clean solution. Although regarded as a promising photocatalyst, the low specific surface area of g-C₃N₄ crucially restrains its photocatalytic performance. The macro-mesoporous architecture provides effective channels for mass transfer and full-light utilization and improved the efficiency of the photocatalytic reaction. Herein, g-C₃N₄ with an inverse opal (IO) structure was rationally fabricated using a well-packed SiO₂ template, which displayed an ultrahigh surface area (450.2 m²·g^-1) and exhibited a higher photocatalytic H₂ evolution rate (21.22 μmol·h^-1), almost six times higher than that of bulk g-C₃N₄ (3.65 μmol·h^-1). The IO g-C₃N₄ demonstrates better light absorption capacity than bulk g-C₃N₄, primarily in the visible spectra range, owing to the multiple light scattering effect of the three-dimensional (3D) porous structure. Meanwhile, a lower PL intensity, longer emission lifetime, smaller Nyquist semicircle, and stronger photocurrent response (which synergistically give rise to the suppressed recombination of charge carriers) decrease the interfacial charge transfer resistance and boost the formation of photogenerated electron-hole pairs. Moreover, the existing N vacancies intensify the local electron density, helping increase the number of photoexcitons. The N₂ adsorption-desorption test revealed the existence of ample mesopores and macropores and high specific surface area in IO g-C₃N₄, which exposes more active edges and catalytic sites. Optical behavior, electron paramagnetic resonance, and electrochemical characterization results revealed positive factors, including enhanced light utilization, improved photogenerated charge separation, prolonged lifetime, and fortified IO g-C₃N₄ with excellent photocatalytic performance. This work provides an important contribution to the structural design and property modulation of photocatalysts.      

一维碳纳米管/二维二硫化钼混合维度异质结的原位制备及其电荷转移性能

一维(1D)材料与二维(2D)材料的结合可形成独特的混合维度异质结,其在继承2D/2D范德瓦尔斯异质结的独特物性之外,还具有丰富的堆叠构型,为进一步调控异质结的结构及性能提供了新的可操控自由度。p型1D单壁碳纳米管(SWCNT)与n型2D二硫化钼(MoS₂)的结合,为调控异质结的能带结构及器件性能提供了丰富的选择。本文直接在高密度、手性窄分布的SWCNT定向阵列及无序薄膜表面原位生长MoS₂,制备出高质量1D SWCNT/2D MoS₂混合维度异质结。深入分析形核点的表面形貌与结构,提出了“吸附-扩散-吸附”生长机制,用于解释混合维度异质结的生长。利用拉曼光谱分析,证实SWCNT与MoS₂间存在显著的电荷转移作用,载流子可在界面处快速传输,为后续基于此类1D/2D异质结的新型电子及光电器件的设计与制备提供了新思路。     

有机配体表面改性NiCo2O4纳米线用于水全分解

由于水分解在绿色能源领域的重要作用,能够在碱性介质中进行析氢(HER)和析氧(OER)反应的双功能电催化剂具有重要的应用价值。本文报道一种具有丰富缺陷的表面改性NiCo₂O₄纳米线(NWs),在碱性介质中作为一种高效的整体水裂解电催化剂。X射线光电子能谱(XPS)分析表明,Co²⁺/Co³⁺比值的增加是表面修饰NiCo₂O₄纳米线具有优异双功能电催化性能的重要原因。结果表明,在1.0 mol·L^-1 KOH溶液中,通过有机配体主导的表面改性,优化后的NiCo₂O₄纳米线在电流密度达到10 mA·cm^-2时的HER过电位仅为83 mV,OER过电位仅为280 mV。更重要的是,有机配体表面改性后的NiCo₂O₄纳米线表现出了出色的水分解性能,在2.1 V电压下达到了100 mA·cm^-2的电流密度。目前的工作凸显了提高NiCo₂O₄ NWs尖晶石结构中Co²⁺含量对促进整体水裂解的重要性。     

高催化活性2D/2D Ti3C2/Bi4O5Br2纳米片异质结的构建及其可见光催化去除NO

This study concentrated on the production of a two-dimensional and two-dimensional (2D/2D) Ti₃C₂/Bi₄O₅Br₂ heterojunction with a large interface that applied as one of the novel visible-light-induced photocatalyst via the hydrothermal method. The obtained photocatalysts enhanced the photocatalytic efficiency of the NO removal. The crystal structure and chemical state of the composites were characterized using X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS). The results showed that Ti₃C₂, Bi₄O₅Br₂, and Ti₃C₂/Bi₄O₅Br₂ were successfully synthesized. The experimental results of scanning electron microscopy (SEM) and transmission electron microscopy (TEM) showed that the prepared samples had a 2D/2D nanosheet structure and large contact area. This structure facilitated the transfer of electrons and holes. The solar light absorptions of the samples were evaluated using the UV-Vis diffuse reflectance spectra (UV-Vis DRS). It was found that the absorption band of Ti₃C₂/Bi₄O₅Br₂ was wider than that of Bi₄O₅Br₂. This represents the electrons in the Ti₃C₂/Bi₄O₅Br₂ nanosheet composites were more likely to be excited. The photocatalytic experiments showed that the 2D/2D Ti₃C₂/Bi₄O₅Br₂ composite with high photocatalytic activity and stability. The photocatalytic efficiency of pure Bi₄O₅Br₂ for the NO removal was 30.5%, while for the 15%Ti₃C₂/Bi₄O₅Br₂ it was 57.6%. Moreover, the catalytic reaction happened in a short period. The concentration of NO decreased exponentially in the first 5 min, which approximately reached the final value. Furthermore, the stability of 15%Ti₃C₂/Bi₄O₅Br₂ was favorable: the catalytic rate was approximately 50.0% after five cycles of cyclic catalysis. Finally, the scavenger experiments, electron spin resonance spectroscopy (ESR), transient photocurrent response, and surface photovoltage spectrum (SPS) were applied to analyze the photocatalytic mechanism of the composite. The results indicated that the 2D/2D heterojunction Ti₃C₂/Bi₄O₅Br₂ improved the separation rate of the electrons and holes, thus enhancing the photocatalytic efficiency. In the photocatalytic reactions, the photogenerated electrons (e⁻) and superoxide radical (·O₂⁻) were critical active groups that had a significant role in the oxidative removal of NO. The in situ Fourier-transform infrared spectroscopy (in situ FTIR) showed that the photo-oxidation products were mainly NO₂⁻ and NO₃⁻. Based on the above experimental results, a possible photocatalytic mechanism was proposed. The electrons in Bi₄O₅Br₂ were excited by visible light. They jumped from the valence band (VB) of Bi₄O₅Br₂ to the conduction band (CB). Then, the photoelectrons transferred from the CB of Bi₄O₅Br₂ to the Ti₃C₂ surface, which significantly promoted the separation of the electron-hole pairs. Therefore, the photocatalytic efficiency of Ti₃C₂/Bi₄O₅Br₂ on NO was significantly improved. This study provided an effective method for preparing 2D/2D Ti₃C₂/Bi₄O₅Br₂ nanocomposites for the photocatalytic degradation of environmental pollutants, which has great potential in solving energy stress and environmental pollution.