Search

A series of covalent organic frameworks (COFs) with β‐ketoenamine linkages named TpTt‐COF, TAPT‐COF, and TpPa‐1 were constructed for photocatalytic H2O2 generation in pure water and ambient air under visible light. Among them, TpTt‐COF performed striking H2O2 yield of 2647 μmol L−1, which is 3.5, 17.5, and 176.5‐fold those of TAPT‐COF, TpPa‐1, and bulk g‐C3N4, respectively, attributing to the electron‐deficient trait, short charge diffusion distance, and the narrowest bandgap of TpTt‐COF. Additionally, to achieve the facile recovery, TpTt‐COF was firmly and evenly anchored on melamine sponges (MS) because plenty of amino groups on the surface of MS could be involved in the β‐ketoenamine formation and guide the synthesis of TpTt‐COF on MS. The corresponding H2O2 evolution over this photocatalyst monolith is also respectable and can be well repeated at least four times. This work is quite instructive for photocatalyst construction based on covalent organic frameworks and facile photocatalytic applications. [ABSTRACT FROM AUTHOR]

Cellulose‐derived carbon (CC) dot‐directed growth of ZnIn2S4 was achieved through hydrothermal treatment of carboxylated cellulose followed by in situ growth of ZnIn2S4 nanosheets. The carbon dots inherited from carboxylated cellulose equip plenty of surface carboxyl groups, which induce the ionic interaction with Zn2+ and In3+ and the guided growth of ZnIn2S4. As a result, the nanosheets of ZnIn2S4 are evenly and intimately grown on the small carbon dots, providing high‐speed channels for charges transfer. In conjunction with the reinforced visible‐light capture and good conductivity of carbon dots, the resultant CC/ZnIn2S4 shows an outstanding photocatalytic activity. As a proof‐of‐concept, visible‐light‐driven 5‐hydroxymethylfurfural oxidation into 2,5‐diformylfuran was conducted. The evolution of 2,5‐diformylfuran over the optimal CC/ZnIn2S4 sample can reach ∼2980 μmol g−1, about 3.4 times that of pristine ZnIn2S4. Additionally, the apparent quantum yield could attain 3.4 % at a wavelength of 400 nm. [ABSTRACT FROM AUTHOR]