Persistent Luminescent Nanoparticle-Coated Metal–Organic Frameworks for Round-the-Clock Photocatalytic Degradation of Pollutants

Round-the-clock photocatalysts based on persistent luminescent nanoparticles (PLNPs) have great potential for water treatment and energy conservation, with continuous photocatalytic activity even at night or under dark conditions. However, their round-the-clock photocatalytic efficiency is still not high enough owing to the short persistent luminescence time, the low specific surface area, and the fast recombination rate of the light-generated e–/h+ pairs. Furthermore, no PLNP combinations with metal–organic frameworks (MOFs) for photocatalytic application have been reported as of yet. Here, we report a round-the-clock composite photocatalyst based on Zn3Ga2Ge2O10:0.5% Mn combined with NH2-MIL-101(Fe) via covalent bonding for the photo-degradation of RhB and the photo-reduction of Cr(VI). The PLNPs/MOFs composite photocatalyst exhibits high photocatalytic activity in the dark for more than 12 h due to the long afterglow time of more than 16 days of Zn3Ga2Ge2O10/0.5% Mn, the efficient persistent luminescence resonance energy transfer between PLNPs and MOFs, the large specific surface area of MOFs, the large number of active transition metal sites of MOFs, and the decrease of the photogenerated e–/h+ pair binding rate. The combination of PLNPs/MOFs provides a strategy for developing highly efficient round-the-clock photocatalysts, which offer great potential in environmental protection and utilization of solar energy.