Carbon Nitride-Perovskite Composites: Evaluation and Optimization of Photocatalytic Hydrogen Evolution in Saccharides Aqueous Solution

• Main Authors: Andrea Speltini, Lidia Romani, Daniele Dondi, Lorenzo Malavasi, Antonella Profumo
• Format: Article
• Language: English
• Published: MDPI AG 2020-10-01
• Series: Catalysts
• Subjects: hydrogen; catalyst; photocatalysis; biomass; solar light; perovskite
• Online Access: https://www.mdpi.com/2073-4344/10/11/1259

The application of hybrid photocatalysts made of carbon nitride and lead-free perovskites, namely DMASnBr₃/g-C₃N₄ and PEA₂SnBr₄/g-C₃N₄, for the H₂ evolution from saccharides aqueous solution is described. The novel composites were tested and compared in terms of hydrogen evolution rate (HER) under simulated solar light, using Pt as a reference co-catalyst, and glucose as a representative sacrificial biomass. The conditions were optimized to maximize H₂ generation by a design of experiments involving catalyst amount, glucose concentration and Pt loading. For both materials, such parameters affected significantly H₂ photogeneration, with the best performance observed using 0.5 g L⁻¹ catalyst, 0.2 M glucose and 0.5 wt% Pt. Under optimized conditions, DMASnBr₃/g-C₃N₄ showed a 5-fold higher HER compared to PEA₂SnBr₄/g-C₃N₄, i.e., 925 µmoles g⁻¹ h⁻¹ and 190 µmoles g⁻¹ h⁻¹, respectively (RSD ≤ 11%, <i>n</i> = 4). The former composite, which affords an HER 15-fold higher in aqueous glucose than in neat water, provided H₂ also with no metal co-catalyst (around 140 µmoles g⁻¹ h⁻¹), and it was reusable for at least three photoreactions. Encouraging results were also collected by explorative tests on raw starch solution (around 150 µmoles g⁻¹ h⁻¹).