Extrusion-based Additive Manufacturing of Three-dimensional MoSe2-nanosheet-coated TiO2 Hetero-structures for Photocatalytic CO2 Reduction

Abstract

Abstract Extrusion-based additive manufacturing (EAM) provides design freedom and facilitates the production of complicated structures that are often challenging to produce using conventional processing methods. In this study, a TiO2 feedstock was developed by mixing TiO2 with a binder and optimized for extrusion. To maximize the reaction efficiency, we fabricated three-dimensional (3D) structures for photocatalytic CO2 reduction based on the designed model. To further enhance the photocatalytic CO2 reduction efficiency, we introduced a heterostructure by hydrothermally synthesizing MoSe2, a transition metal dichalcogenide (TMD), on the TiO2 surface. MoSe2, which is known for its affordability in fabrication heterostructures, high electrical conductivity, expanded light absorption range, and reduced bandgap, has the potential to enhance photocatalytic efficiency. The effectiveness of various TiO2–MoSe2 3D structural designs for CO2 reduction was evaluated. A custom-made stainless-steel reactor was used for CO2 reduction under UV-vis irradiation, followed by gas chromatography analysis of the produced gases. The optimized structure exhibited remarkable CO2 selectivity, reaching approximately 82%, demonstrating the feasibility of using EAM for fabricating 3D structures for photocatalytic CO2 reduction.