Suman Pokhrel, Jakob Stahl, Lizhuo Wang, Rui Tang, Haoyue Sun, Malte Schalk, Marco Schowalter, Andreas Rosenauer, Jun Huang, Johannes Kiefer, Johannes Birkenstock, Lutz Mädler
Advanced Functional Materials (2024): 2411521
https://doi.org/10.1002/adfm.202411521
The innovative development of reactive-spray systems for gas-phase production of metal sulfides are potential materials for next-generation technologies. These flame-synthesized sulfides (doped, functionalized, and heterogeneously mixed derivatives) hold significant potential as photocatalysts for water splitting. The knowledge acquired from nonaqueous precursor-solvent and high-temperature aerosol chemistries, optimal process parameters are established to generate In2-(4/3)xSnxS3, solid-solutions. The thermally driven reducing gas-phase reactions are controlled through fuel/oxygen ratio. Particles characterizations (X-ray diffraction, transmission electron microscopy (TEM) and imaging) revealed structural stability and crystallinity. The In2-(4/3)xSnxS3, at higher Sn doping had enhanced photoexcitation. Donor-acceptor levels within the material facilitated electron-hole pair trapping, crucial for redox reactions. With suitable band gap energies for water oxidation (1.9-1.1 eV) closely matched flat band potentials (4.38-4.67 eV) for redox reactions. The powder characterization showed 8% In2O3 in InSn0.75S3 after photocatalysis due to S-degradation in the initial light “on/off cycles”. The pioneering process of employing oxygen-deficient reducing flame enabled a series of photo-catalytically active metal sulfide nanoparticles with work function energies in the range of 5.19-5.37 eV. This synthesis strategy holds the potential for impactful advancements in both industry and R&D, addressing the urgent need for new materials capable of inducing water oxidation under visible light.
