Porous and conductive SnO2 ceramics as a promising nanostructured substrate to host photocatalytic hematite coatings: Towards low cost solar-driven water splitting

• Published in: Catalysis communications Vol. 174; p. 106593
• Main Authors: Bondarchuk, Alexander N., Corrales-Mendoza, Iván, Aguilar-Martínez, Josué A., García-Pérez, Ulises M., Marken, Frank
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 01.01.2023; Elsevier
• Subjects: Hematite; Photocatalysis; Solar energy; Tin-dioxide ceramics; Water splitting; Hematite; Tin-dioxide ceramics; Water splitting; Photocatalysis; Solar energy
• ISSN: 1566-7367; 1873-3905
• DOI: 10.1016/j.catcom.2022.106593

Commercially viable generation of “green” hydrogen fuel by solar-driven water splitting requires the design of low-cost photoelectrodes and photo-devices with high photoelectrochemical performance. In this regard, conductive and easily fabricated 3D-oxide ceramics with nanosized grains and high porosity are promising as a substrate with a large surface area to host photocatalytic coatings. To test this approach, hematite photoelectrodes have been grown by metal-organic chemical vapor deposition onto free-standing SnO2-based ceramics. The photoanodes formed onto Sb2O5-SnO2, CuO-Sb2O5-SnO2, and on MoO3-Sb2O5-SnO2 substrates in aqueous 1 M NaOH under 1 sun irradiation exhibit photocurrent densities of 0.44 mA/cm2, 0.56 mA/cm2, and 0.39 mA/cm2 at 1.23 V vs. RHE, respectively. The porosity of ceramics results in the 3D growth of a thin hematite coating on ceramic grains in the substrate to a depth of ca. 3 μm. The obtained photoelectrodes are discussed based on the data of photoelectrochemical measurements, X-ray diffraction (XRD), scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDS), and Raman spectroscopy. Routes to improved performance are discussed. •Porous and conductive ceramics were applied as substrates to host hematite coating•Hematite layer on grains has a thickness of several tenths of nanometers or less•Photoactive layer grows into ceramic substrate to a depth of some micrometers•Obtained Fe2O3-photoelectrodes show 0.56 mA cm−2 at 1.23 V vs RHE (AM1.5G irradiation)