Synthesis of a yolk-shell metal-organic framework heterostructured photocatalyst

One of the most promising solutions to the energy crisis is to convert CO₂ to valuable chemicals by means of solar energy. Various photocatalysts, ranging from semiconducting materials like TiO₂ to metal-incorporating zeolites have been investigated for their activity in photocatalytic CO₂ reduction. However, most of the photocatalysts investigated are only active in the UV region and their efficiency for CO₂ reduction is still quite low. This has been partly attributed to weak CO₂ adsorption on the (photo)catalyst surface. Metal-organic frameworks (MOF), a class of porous crystalline materials formed by a network of metal ions/clusters linked by polydentate organic molecules, have emerged as an exciting potential CO₂ adsorbent. In this investigation we report the synthesis of a visible light active bi-functional heterostructured photocatalyst. A yolk-shell carbon@TiO₂ core was hydrothermally synthesized, while the MOF shell was prepared via a direct and in direct synthesis approach. X-ray powder diffraction confirmed the identity of the synthesized materials. While FE-SEM and ultrahigh resolution STEM equipped with EDS provided evidence of successful core-shell morphology.