光催化作为一种环境友好技术,在解决环境污染和能源匮乏问题方面展现出巨大应用潜力.TiO2因其化学稳定性、无毒和低成本被广泛应用于能源转换和污染物降解等领域,但其快速的电子-空穴复合与低太阳能利用率等限制了其在光催化中的潜在应用.因此,寻找新的有优越可见光活性的催化剂是一个挑战.最近,(BiO)2CO3因其独特的形貌、化学稳定性和较高的催化效率成为有前景的光催化剂.然而,(BiO)2CO3较大的带隙限制了对太阳光的利用,快速的电子-空穴复合阻碍了光催化性能的提高.因此,提高(BiO)2CO3的光催化效率是当务之急.近期研究表明,通过与氧化石墨烯杂交提高载流子的分离能力,可有效增强光催化性能.基于此,我们设计并合成了一种氮掺杂的(BiO)2CO3与氧化石墨烯(GO)耦合的新型光催化剂(N-BOC-GO).首先,通过一步水热法合成了N-BOC-GO微球.N-BOC-GO光催化剂对NO可见光光催化去除性能达到62%.采用X射线衍射(XRD)、X射线光电子能谱(XPS)、扫描电子显微镜(SEM)、紫外-可见漫反射光谱(UV-Vis)和光致发光光谱(PL)等表征手段研究了N-BOC-GO的光催化性能增强机制.从N-BOC-GO的XRD谱中没有发现GO的衍射峰,说明加入的GO分散度高;N-BOC-GO中的BOC晶格参数没有发生变化,说明GO没有进入BOC晶格,但加入GO增强了N-BOC的结晶度.XPS结果表明,与N-BOC相比,N-BOC-GO的峰位置发生了明显位移,表明N-BOC和GO之间存在强相互作用.此外,FT-IR和拉曼光谱证明了在复合物中存在GO.SEM表明,N-BOC规则地团聚成微球,且微球被固定在有褶皱的GO片上.这说明GO与N-BOC的作用是静电作用或物理作用,在光激发过程中有利于N-BOC微球上的电子转移到GO片上.UV-Vis图谱中,N-BOC-GO表现出明显增强的可见光吸收,说明加入GO会明显提高N-BOC的吸收能力.此外,3D分层结构会通过SSR效应提高光吸收.从PL?
Hierarchical microspheres of a graphene oxide(GO) coupled to N‐doped(BiO)2CO3 composite(N‐BOC‐GO) was synthesized by a simple hydrothermal approach. The N‐BOC‐GO composite gave enhancement in photocatalytic activity compared to the pure BOC and N‐BOC samples. With 1.0wt% GO, 62% NO removal was obtained with N‐BOC‐GO. The factors enhancing the photocatalytic performance were the high electron‐withdrawing ability and high conductivity of GO and improved visible light‐harvesting ability of N‐BOC‐GO with a 3D hierarchical architecture due to the surface scattering and reflecting(SSR) effect. An effective charge transfer from N‐BOC to GO was demonstrated by the much weakened photoluminescene intensity of the N‐BOC‐GO composite. This work highlights the potential application of GO‐based photocatalysts in air purification.