Reduced Graphene Oxide-TiO2 Nanocomposite Research Papers (original) (raw)

In this comprehensive study, the influence of titanium dioxide (TiO2) dopants decorated on Reduced Graphene Oxide (rGO) via spin coating technique as an efficient photoelectrode in DSSCs was investigated in detail. This study aims to determine the optimum spinning duration for decorating TiO2 onto rGO nanosheet photoanode for high DSSCs performance. The rGO nanosheet was prepared using the electrodeposition method. A dropped of 0.2 wt% of TiO2 solution was absorbed using micro-pipette (0.1 μl) and continuously applied on FTOrGO surface with the rate of 0.1 μl/5s. The spinning duration was varied from 10 to 50 s, and resultant samples were labelled as Lt, where t= 10, 20, 30, 40 and 50s, respectively. The experimental results showed that TiO2 decorated rGO nanosheet photoanode for 30s spinning duration exhibited a maximum power conversion efficiency of 9.98% than that of pure rGO nanosheet photoanode (4.74%) under 150 W of xenon irradiation, which is about 2.1 times improvement in DSSCs performance. Ti4+ ion was decorated onto rGO nanosheet leading to the highest interactions with the O-H functional group or Ti4+ could react with the epoxide or phenolic groups in rGO forming the Ti-O-C bonds.

In particular, the dye-sensitised solar cells
(DSSCs) have a high potential in the rational energy conversion
efficiency to secure our sustainable energy source.
In the present study, advanced radio frequency (RF) magnetron
sputtering technique was applied to incorporate
titanium dioxide (TiO2) dopants into reduced graphene
oxide (rGO) nanosheet for improving the power conversion
efficiency (PCE) of DSSCs device. An optimum TiO2
content incorporated onto rGO nanosheet plays an important
role in improving the PCE of DSSCs by minimising
the recombination losses of photo-induced charge carriers.
Based on the results obtained, 40-s sputtering duration for
incorporating TiO2 dopants onto rGO nanosheet exhibits a
maximum PCE of 8.78% than that of pure rGO film
(0.68%). In fact, the presence of optimum content of TiO2
dopants within rGO nanosheet could act as mediators for
efficient separation photo-induced charge carriers. However,
the excessive of sputtering duration (e.g. 60 s) of
TiO2 dopants onto rGO nanosheet results higher charge
recombination and lowers the PCE of DSSCs (5.39%).

Self-organized V-N co-doped TiO2 nanotube arrays (TNAs) with various doping amount were synthesized by anodizing
in association with hydrothermal treatment. Impacts of V-N co-doping on the morphologies, phase structures, and
photoelectrochemical properties of the TNAs films were thoroughly investigated. The co-doped TiO2 photocatalysts
show remarkably enhanced photocatalytic activity for the CO2 photoreduction to methane under ultraviolet illumination.
The mechanism of the enhanced photocatalytic activity is discussed in detail.

In a previous paper (Shalaby A, Yaneva V, Staneva A, Aleksandrov L, Iordanova R, Dimitriev Y, Nanoscience & nanotechnology – nanostructured materials application and innovation transfer (14), ISSN 1313-8995, 2014) we studied reduced graphene oxide (RGO)/SiO2 composite material by adding a small amount of RGO to silica in order to avoid the aggregation process and to solve the problems connected with the exfoliation and distribution of the sheets inside the composites. But from a practical point we needed to study the effect of high amounts of RGO on the composites at different temperatures. The purpose of this investigation is to study the effect of RGO on phase transformations of the composites heated at 200, 400 and 800 C. The sol-Gel method was used to obtain the RGO/SiO2 composite by mixing high amounts of RGO with tetraethyl orthosilicate (TEOS). Data are presented for the transformation of the nanocomposites with increasing temperature in air atmosphere. RGO nanosheets were prepared by chemical exfoliation of purified natural graphite using the Hummers and Offeman method (Hummers WS, Offeman RE, J Am Chem Soc 80:1339, 1958) to obtain graphite oxide. Then the material was exfoliated to reduced graphene nanosheets by ultrasonication and reduction process using sodium borohydride (NaBH4). Characterization of the material was performed by X-ray powder diffraction (XRD),

- by Ahmed Shalaby
- •
- Reduced Graphene Oxide-TiO2 Nanocomposite