Surface modification of TiO 2 nanosheets with fullerene and zinc-phthalocyanine for enhanced photocatalytic reduction un
- PDF / 3,701,690 Bytes
- 10 Pages / 595.276 x 793.701 pts Page_size
- 53 Downloads / 214 Views
Published online 21 September 2020 | https://doi.org/10.1007/s40843-020-1436-5
SPECIAL TOPIC: Advanced Photocatalytic Materials
Surface modification of TiO2 nanosheets with fullerene and zinc-phthalocyanine for enhanced photocatalytic reduction under solar-light irradiation 1,2
1
1,2
1*
Liping Liu , Xiaolong Liu , Yongqiang Chai , Bo Wu and Chunru Wang ABSTRACT High-efficiency photocatalysts are of great importance to satisfy the requirements of green chemistry nowadays. Here we reported a novel solar-driven photocatalyst fabricated by a facile surface modification method, with the two-dimensional carboxylated zinc phthalocyanine-carboxylated C60-titanium dioxide (ZnPc-C3-TiO2) nanosheets, in which the surface modifications of ZnPc and C60 derivative were designed to extend the absorption range and promote charge separation, respectively. Benefiting from the unique structure and positive synergetic effect, the ZnPc-C3-TiO2 nanocomposite shows promising applications in selective reduction of nitroarenes for high-value-added aromatic amines under solar light. Especially, for the photocatalytic reduction of nitrobenzene to aniline, the ZnPc-C3-TiO2 nanocomposite possesses both high efficiency and selectivity (up to 99%). Keywords: fullerene, TiO2 nanosheet, electron-hole separation, photocatalytic activity
INTRODUCTION Photocatalysis, which involves the absorption of light by one or more reacting species, is a green and sustainable technique to converse solar energy into chemical energy [1]. In recent years, scientific communities have focused intense interests on photocatalytic fuel generation, such as water splitting [2,3] and carbon dioxide reduction [4– 7], yet the inadequacy in efficiency and endurance hampers their further application. Meanwhile, photocatalytic reduction techniques have shown great potential in fine chemical synthesis of high-value-added organic compounds [8,9]. For instance, the traditional catalytic hy-
1*
drogenation, which usually adopts noble metal as the catalysts under harsh condition, is widely adopted for reducing nitrobenzene to aniline. However, with the development of photocatalysts, a more environmentfriendly and low-cost approach to nitrobenzene reduction is anticipated [10]. Titanium dioxide (TiO2) is a widely studied semiconductor material featuring high stability, easy preparation and low toxicity. Unfortunately, the photocatalytic performance of pristine TiO2 is largely restricted by its broad bandgap (3.2 eV) and low quantum efficiency [11]. In fact, the construction of TiO2-based nanocomposites, such as coupling with narrow band semiconductors or doping with non-metal/metal elements and loading with organic photosensitizer, has been proved to be effective strategies to boost the photocatalytic activity [12–15]. In the pursuit of highly efficient photocatalysts, the binary nanocomposites of TiO2 modified with carbon nanomaterials, such as fullerene, carbon nanotube, and graphene, have drawn numerous attentions [16]. In particular, the C60-modified TiO2 nanocomposites
