Seite - 130 - in Photovoltaic Materials and Electronic Devices

Heterojunctionsofp-BiOI Nanosheets/n-TiO2 Nanofibers: Preparation andEnhancedVisible-Light PhotocatalyticActivity KexinWang,ChangluShao,XinghuaLi,FujunMiao,NaLuandYichunLiu Abstract: p-BiOI nanosheets/n-TiO2 nanofibers (p-BiOI/n-TiO2 NFs) have been facilely prepared via the electrospinning technique combining successive ionic layer adsorption and reaction (SILAR). Dense BiOI nanosheets with good crystalline and width about 500 nm were uniformly assembled on TiO2 nanofibers at room temperature. Theamountof theheterojunctionsandthespecificsurfaceareawere well controlled by adjusting the SILAR cycles. Due to the synergistic effect of p-n heterojunctions and high specific surface area, the obtained p-BiOI/n-TiO2 NFs exhibited enhanced visible-light photocatalytic activity. Moreover, the p-BiOI/n-TiO2 NFs heterojunctions could be easily recycled without decreasing the photocatalytic activity owing to their one-dimensional nanofibrous structure. Based on the above, the heterojunctions of p-BiOI/n-TiO2 NFs may be promising visible-light-driven photocatalysts for converting solar energy to chemical energy in environmentremediation. Reprinted from Materials. Cite as: Wang, K.; Shao, C.; Li, X.; Miao, F.; Lu, N.; Liu,Y.Heterojunctionsofp-BiOINanosheets/n-TiO2 Nanofibers: Preparationand EnhancedVisible-LightPhotocatalyticActivity. Materials2016, 9, 90. 1. Introduction Semiconductorphotocatalystshavebeenpromisingmediatodegradepollutants through converting solar energy to chemical energy [1]. In recent years, bismuth oxyhalidesBiOX(X=Cl,Br, I),asp-typesemiconductors,haveattractedconsiderable attentions owing to their unique layered crystal structure and indirect optical transitioncharacteristic. The layerstructureconsistsof (Bi2O2)2+ layers interleaved by double halogen atoms layers, which can present an internal static electric field andinduce theseparationofphotogeneratedcarriesmoreefficiently. Furthermore, the indirect transition band gap is necessary for electrons to be emitted to valence bandbyacertaink-spacedistance,whichreduces therecombinationprobabilityof photoelectronsandholes [2,3]. Theseadvantages leadtoremarkablephotocatalytic activities in degradation of organic compounds [4–7]. Notably, the p type BiOI (p-BiOI) nanostructures have the narrowest band gap (~1.8 eV) among BiOX (X=Cl, Br, I)nanostructures. Therefore, thep-BiOInanostructuresareconsideredexcellent 130