In this context, well-defined crystalline covalent organic frameworks 10 (COFs) composed of organic building units linked by covalent bonds can act as promising photocatalysts for hydrogen evolution with tunable photophysical and optoelectronic properties. 11- COFs can show light harvesting properties with broad absorption and effective electron transfer to the catalyst surface with enhanced charge mobility. 2D-COFs contain planar layered framework which can be chemically tuned with diverse functionalities based on varied synthetic modulation. Different molecular design strategies involving donor-acceptor moieties, photosensitizing entities and p-conjugated extended backbone in the building blocks have been explored to synthesize photocatalytic COFs. 1,13,19-23 Beside these, the interplay of several factors including band gaps, charge carrier generation, transportation and separation, stability, surface area and morphology also affect the photocatalytic performance. Different COFs based on numerous moieties such as hydrazone, sulfone, azine, thiophene, cyano, imine, and diacetylene have been reported and showed growing photocatalytic hydrogen evolution rates over the recent years. However, as COFs are built from reversible linkages there are concerns about their long-term stability under photocatalytic conditions. Thus, an innovative design approach that can offer functionality, high stability as well as potential for practical applicability is needed. In recent years, multi-component reactions (MCR), wellknown in organic synthesis, have been developed to construct robust cyclic linkages in COFs with high stability. This method operates in a one-pot cascade manner using at least three components to produce a single product rendering it an atom-economic synthetic route. MCR also provides an opportunity to decorate the pores of COFs with different functionalities without the need of post synthetic modifications. Our group has recently reported MCR-COFs based on the Doebner and Povarov reactions which showed long-term photocatalytic hydrogen peroxide production and selective oxidation reactions. In this study several MCR-COFs with different pore functionalities and enhanced stability were applied for longterm solar-driven H2 production in water and seawater. We synthesized five microporous 4-substituted quinoline linked COFs (PCOF-1-5), with pending benzene, 2 or 4-pyridine, imidazole and pentafluorobenzene groups via the three-component Povarov reaction. It was observed that the photocatalytic H2 evolution vary dependent on the different pore functionality in MCR-COFs. Among these, imidazole functionalized COF exhibit the highest surface area, wettability and the best photocatalytic H2 evolution activity. It is also seen that the durability and recyclability of MCR-COFs are superior compared to the analogous imine-based COF. MCR-COFs display photostability and steady long-term H2 production up to almost 15 days.