Rare-Earth Doped Transition Metal–Organic Frameworks for Photocatalytic Hydrogen Evolution: Applications and Integration in the Global Hydrogen Economy

Global decarbonization efforts have intensified interest in hydrogen (H₂) as a clean energy carrier, yet the practical value of any hydrogen-splitting technology depends on how the hydrogen produced is ultimately deployed across power, transport, and industrial sectors. Building on our previously reported rare-earth doped transition metal–organic framework (RE–TM–MOF) system for photocatalytic hydrogen evolution, this perspective examines in detail the downstream application landscape for hydrogen generated via photocatalytic and electrocatalytic water-splitting routes. We describe six major application domains — power generation, transportation, industrial decarbonization, chemical feedstock, energy storage, and decentralized solar-to-hydrogen generation — and compare photocatalytic MOF-based routes against established electrolysis technologies in terms of efficiency, cost, and infrastructure readiness. We argue that while electrolysis remains the nearer-term scalable pathway, RE–TM–MOF and related photocatalytic architectures are positioned to fill a complementary niche in low-infrastructure, high-insolation deployment scenarios, pending further pilot-scale validation.