9:30 AM - 9:45 AM
▲ [13a-A303-1] Fabrication of MoS2 and p-type Silicon Heterojunction for Photocatalytic Hydrogen Evolution Reaction in Acidic Medium
Keywords:Semiconductor, photocatalysis
Introduction: Recently two directional layered materials have been explored as novel photocatalyst for hydrogen generation and several other applications. Among these, n-type molybdenum disulphide (MoS2) is being widely studied for its excellent tunable optoelectronic and photochemical properties. It has a direct band gap of 1.8 eV which makes it a promising candidate in future of optoelectronic devices. Again, it can be combined with conventional semiconductors like silicon to fabricate a two dimensional/ three-dimensional (2D/3D) heterojunction for optoelectronics and photocatalytic application. In this study we explored the fabrication of a 2D/3D heterojunction and the photocatalytic hydrogen evolution reaction (HER).
Experimental: Molybdenum Oxide (MoO3) was deposited on the surface of p-type Silicon using thermal evaporator. MoS2 was deposited in a Sulphur rich condition. The reverse side of the p-type Silicon was roughened and ohmic contact was made using Indium-Gallium mixture. Connection was given using a copper wire. An epoxy resin layer was coated on top of it. A linear sweep voltammetry analysis was done of the device thus made, in 0.5 M Sulphuric acid (0.5M H2SO4) in dark and light conditions to check the light response of the device.
Results and discussion: Figure 1a shows the schematic of a MoS2 and p-type Silicon heterostructure. Figure 1b shows the Raman spectrum of the synthesized MoS2 and p-type Silicon heterostructure by the sulfurization process. Formation of few-layers MoS2 on Silicon wafer surface was confirmed. Figure 1c shows the hydrogen evolution reaction in the 0.5M H2SO4 using the MoS2/Si as photocathode. It is evident that the device showed an increase in current when it was exposed to light. The potential at which hydrogen evolution began also decreased in the presence of light.
Experimental: Molybdenum Oxide (MoO3) was deposited on the surface of p-type Silicon using thermal evaporator. MoS2 was deposited in a Sulphur rich condition. The reverse side of the p-type Silicon was roughened and ohmic contact was made using Indium-Gallium mixture. Connection was given using a copper wire. An epoxy resin layer was coated on top of it. A linear sweep voltammetry analysis was done of the device thus made, in 0.5 M Sulphuric acid (0.5M H2SO4) in dark and light conditions to check the light response of the device.
Results and discussion: Figure 1a shows the schematic of a MoS2 and p-type Silicon heterostructure. Figure 1b shows the Raman spectrum of the synthesized MoS2 and p-type Silicon heterostructure by the sulfurization process. Formation of few-layers MoS2 on Silicon wafer surface was confirmed. Figure 1c shows the hydrogen evolution reaction in the 0.5M H2SO4 using the MoS2/Si as photocathode. It is evident that the device showed an increase in current when it was exposed to light. The potential at which hydrogen evolution began also decreased in the presence of light.