engleski

Preliminary characterization investigation of TiO2- SnS2/GO-RGO nanocomposites for hydrogen generation

The development of the future energetic sector requires the higher promotion of the use of alternative fuels, such as hydrogen, specifically ones produced from renewable sources. One of the ambitious ways for such production is photocatalytic water splitting under solar light irradiation. The main means of carrying out the reaction are photocatalytic nanomaterials. The most used photocatalyst is TiO2, which is characterized by UV-light response and high rates of charge recombination. Therefore, it is necessary to combine such material with other semiconducting materials that have high visible- light response and that decrease charge carrier recombination rate. In this work, hydrothermally synthesized TiO2- SnS2/GO-RGO nanomaterial with different ratios of GO-RGO (graphene oxide – reduced graphene oxide) within the samples was subjected to detailed characterization analysis prior to photocatalytic H2 production investigation. The pure components were also examined with the purpose of comparing newly designed and synthetized TiO2-SnS2/GO-RGO. Analyses include the determination of material's thermal stability, morphology, optical and semiconducting properties. SEM analysis showed the presence of GO/RGO layers on a TiO2 surface decorated with SnS2 hexagonal nanoparticles, while UV/Vis diffuse reflectance spectroscopy (DRS) enabled calculation of the material's bandgap (Eg) energy. Results of the FTIR analysis confirmed the presence of the expected functional groups within investigated samples, while high purity and an approximate portion of individual components were determined through TGA measurements. Semiconducting properties were analysed with photoelectrochemical tests that include EIS, CV- LSV, Mott-Schottky, and Open Circuit Potential (OCP) measurements. The results indicate a positive effect of GO-RGO presence on decreasing charge recombination rate and the electron lifetime. All summarized results indicate a promising application of the as-synthesized materials in photocatalytic hydrogen generation processes.

photocatalysis ; graphene ; SnS2 ; hydrogen

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