MOCHAs: An Emerging Class of Materials for Photocatalytic H2 Production

• Published in: Small (Weinheim an der Bergstrasse, Germany) Germany), 2024-08, Vol.20 (33), p.e2400348-n/a
• Main Authors: Nagaraju Myakala, Stephen, Rabl, Hannah, Schubert, Jasmin S., Batool, Samar, Ayala, Pablo, Apaydin, Dogukan H., Cherevan, Alexey, Eder, Dominik
• Format: Article
• Language: English
• Subjects: Bonding strength; Catalysts; Clean energy; coordination polymers; Electron transfer; Emissions; Green hydrogen; Greenhouse gases; Hydrogen bonds; Hydrogen evolution reactions; Hydrogen production; MOCHAs; MOCs; Photocatalysis; silver; Structural integrity; Structural stability; Titanium dioxide; transition metal chalcogenides; water splitting
• ISSN: 1613-6810; 1613-6829; 1613-6829
• DOI: 10.1002/smll.202400348

Production of green hydrogen (H2) is a sustainable process able to address the current energy crisis without contributing to long‐term greenhouse gas emissions. Many Ag‐based catalysts have shown promise for light‐driven H2 generation, however, pure Ag—in its bulk or nanostructured forms—suffers from slow electron transfer kinetics and unfavorable Ag─H bond strength. It is demonstrated that the complexation of Ag with various chalcogenides can be used as a tool to optimize these parameters and reach improved photocatalytic performance. In this work, metal‐organic‐chalcogenolate assemblies (MOCHAs) are introduced as effective catalysts for light‐driven hydrogen evolution reaction (HER) and investigate their performance and structural stability by examining a series of AgXPh (X = S, Se, and Te) compounds. Two catalyst‐support sensitization strategies are explored: by designing MOCHA/TiO2 composites and by employing a common Ru‐based photosensitizer. It is demonstrated that the heterogeneous approach yields stable HER performance but involves a catalyst transformation at the initial stage of the photocatalytic process. In contrast to this, the visible‐light‐driven MOCHA‐dye dyad shows similar HER activity while also ensuring the structural integrity of the MOCHAs. The work shows the potential of MOCHAs in constructing photosystems for catalytic H2 production and provides a direct comparison between known AgXPh compounds. The study introduces metal‐organic‐chalcogenolate assemblies (MOCHAs) as effective catalysts for light‐driven hydrogen evolution from water splitting, unraveling their performance characteristics and discussing their photostability under turnover conditions. Different catalyst‐support sensitization strategies are explored by comparing molecule‐based MOCHA‐dye dyads with heterogeneous MOCHA‐TiO2 composites.