The Photocatalytic and Photoelectrochemical Properties of Combinatorial Density Gradient TiO2-rGO Nanocomposites Using Hydrothermal Synthesis

Abstract

The application of renewable energy has become a global issue in recent years Semiconductor photocatalyst can effectively decompose organic pollutants and split water to harvest hydrogen fuels by solar light However researchers keep exploring the novel materials to overcome nature limitations of materials In order to efficiently obtain an optimal photocatalyst a combinatorial composition spread sample was fabricated to facilitate the exploration of appropriate parameters In this study density gradient rutile TiO2 was grown on silicon substrate by spin coating and hydrothermal method Moreover coupling with density gradient of reduced graphene oxide (rGO) to become a combinatorial density gradient of TiO2-rGO nanorod composites This novel concept is different from the literature of hydrothermal method which only can produce single parameter on one sample and repeat multiple procedures to explore the best condition On the contrary our combinatorial density gradient of TiO2-rGO nanorod composites sample contains a wide range of compositions in a single sample enabling efficient screening of materials for applications Various techniques of XRD SEM FTIR Raman and PL were employed to determine the various characteristics including phases morphologies microstructures optical properties compositions and chemical bondings Photodegradation activities were determined by decomposing methylene blue (MB) under UV light The result shows that coupling with suitable amount of rGO can effectively assist TiO2 to enhance the photocatalytic properties In photoelectrochemical (PEC) reaction the cell was measured with a constant 1 V bias under UV light The measured current of TiO2-rGO nanorod composites was approximately 25 μA/cm2 more than double the value obtained from the pure TiO2 nanorods (approximately 10 μA/cm2)

Date of Award	2016 Aug 26
Original language	English
Supervisor	Kao-Shuo Chang (Supervisor)