Effect of the carbon loading on the structural and photocatalytic properties of reduced graphene oxide-TiO2 nanocomposites prepared by hydrothermal synthesis

被引:15
作者
Gonçalves B.S. [1 ]
Palhares H.G. [1 ,2 ]
Souza T.C.C.D. [2 ,3 ]
Castro V.G.D. [3 ]
Silva G.G. [3 ,4 ]
Silva B.C. [5 ]
Krambrock K. [5 ]
Soares R.B. [2 ]
Lins V.F.C. [2 ]
Houmard M. [6 ]
Nunes E.H.M. [1 ]
机构
[1] Departamento de Engenharia Metalúrgica e de Materiais, Universidade Federal de Minas Gerais, Pampulha, Belo Horizonte, MG
[2] Departamento de Engenharia Química, Universidade Federal de Minas Gerais
[3] Centro de Tecnologia em Nanomateriais (CTNano), Rua Prof. Jo. V. de Me., 1000-Engenho No., Belo Horizonte MG
[4] Departamento de Química, Universidade Federal de Minas Gerais
[5] Departamento de Física, Universidade Federal de Minas Gerais
来源
Journal of Materials Research and Technology | 2019年 / 8卷 / 06期
关键词
Photocatalytic evaluation; Reduced graphene oxide; Sol-gel process; Structural characterization; TiO[!sub]2[!/sub;
D O I
10.1016/j.jmrt.2019.10.020
中图分类号
学科分类号
摘要
This work deals with the preparation of reduced graphene oxide (RGO)-TiO2 composites by a one-step hydrothermal treatment. The effect of the RGO loading on both the structural properties and photocatalytic behavior of RGO-TiO2 is deeply addressed herein. The hydrothermal treatment promoted the reduction of graphene oxide, crystallization of TiO2 into anatase, and anchoring of TiO2 nanoparticles on RGO sheets. It was observed that the prepared anatase particles showed sizes below 10 nm, whereas the RGO sheets displayed thicknesses smaller than 1 nm. The use of RGO at concentrations up to 15 wt% greatly increased the specific surface area of RGO-TiO2. It was demonstrated that the combination of RGO and TiO2 gives rise to materials with improved photocatalytic properties and tailored structural properties. The composite with the highest photoactivity was the one containing an RGO loading of 1 wt%; this composite displayed a photocatalytic rate constant about 9.5 times higher than that evaluated for pure TiO2. This behavior may be related to the stacking of RGO nanosheets when its concentration is above 1 wt%. Moreover, the addition of RGO in excess may prevent the activation of the TiO2 surface by UV light and also decrease the lifetime of the photogenerated electron-hole pairs. Therefore, it appears that 1 wt% is the optimal loading of RGO to obtain a close interfacial contact between RGO and TiO2, leading to both an effective activation of TiO2 by UV radiation and an enhanced charge transfer between RGO and TiO2. © 2019 The Authors.
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页码:6262 / 6274
页数:12
相关论文
共 55 条
[1]  
Hanaor D.A.H., Sorrell C.C., Review of the anatase to rutile phase transformation, J Mater Sci, 46, pp. 855-874, (2011)
[2]  
Esparza D., Zarazua I., Lopez-Luke T., Cerdan-Pasaran A., Sanchez-Solis A., Torres-Castro A., Et al., Effect of different sensitization technique on the photoconversion efficiency of CdS quantum dot and CdSe quantum rod sensitized TiO2 solar cells, J Phys Chem C, 119, pp. 13394-13403, (2015)
[3]  
Houmard M., Riassetto D., Roussel F., Bourgeois A., Berthome G., Joud J.C., Et al., Enhanced persistence of natural super-hydrophilicity in TiO<sub>2</sub>-SiO<sub>2</sub> composite thin films deposited via a sol-gel route, Surf Sci, 602, pp. 3364-3374, (2008)
[4]  
Houmard M., Berthome G., Joud J.C., Langlet M., Enhanced cleanability of super-hydrophilic TiO<sub>2</sub>-SiO<sub>2</sub> composite surfaces prepared via a sol-gel route, Surf Sci, 605, pp. 456-462, (2011)
[5]  
Cai Q., Hu J., Decomposition of sulfamethoxazole and trimethoprim by continuous UVA/LED/TiO<sub>2</sub> photocatalysis: Decomposition pathways, residual antibacterial activity and toxicity, J Hazard Mater, 323, pp. 527-536, (2017)
[6]  
Farner Budarz J., Turolla A., Piasecki A.F., Bottero J.-Y., Antonelli M., Wiesner M.R., Influence of aqueous inorganic anions on the reactivity of nanoparticles in TiO<sub>2</sub> photocatalysis, Langmuir, 33, pp. 2770-2779, (2017)
[7]  
Nakata K., Fujishima A., TiO<sub>2</sub>photocatalysis: Design and applications, J Photochem Photobiol C Photochem Rev, 13, pp. 169-189, (2012)
[8]  
Ohno T., Tokieda K., Higashida S., Matsumura M., Synergism between rutile and anatase TiO<sub>2</sub> particles in photocatalytic oxidation of naphthalene, Appl Catal A Gen, 244, pp. 383-391, (2003)
[9]  
Tang H., Prasad K., Sanjines R., Schmid P.E., Levy F., Electrical and optical properties of TiO<sub>2</sub> anatase thin films, J Appl Phys, 75, pp. 2042-2047, (1994)
[10]  
Scanlon D.O., Dunnill C.W., Buckeridge J., Shevlin S.A., Logsdail A.J., Woodley S.M., Et al., Band alignment of rutile and anatase TiO<sub>2</sub>, Nat Mater, 12, pp. 798-801, (2013)