As a class of the efficacious photocatalysts for watersplitting, conjugated polymers (CPs) have drawn considerable attention in recent years. However, the unexpectedly fast charge recombination always constricts their further application, leading to poor photocatalytic behavior. Here, we report a series of dibenzothiophene-S,S-dioxide-based polymers with electron-property-dependent reactivity as well as their photocatalysis in hydrogen evolution. The results reveal that the introduction of a secondary acceptor unit into the repeating units of a CP skeleton is an effective method to enhance the photocatalytic hydrogen production activity, which is conducive to the separation and transport of photogenerated charge carriers. Therefore, the Pt-free B-SO and C 3 N 3 -SO photocatalysts in an A 1 −π−A 2 form exhibit a competitive hydrogen evolution rate (HER) of 778 and 1603 μmol g −1 h −1 under visible light, respectively. Notably, under the same conditions, the 3 wt % Pt-modified B-SO and C 3 N 3 -SO provide a satisfactory HER of 1253 and 2966 μmol g −1 h −1 , respectively. Our study proffered an effective strategy for enhancing the photocatalytic hydrogen evolution of CPs, which could be used for the design and optimization of other photocatalytic systems.

By using the octadentate ligand tetrakis [(3,5-dicarboxyphenoxy)methyl] methane (H 8 L), a rare (4,8)-scu type microporous coordination polymer, [In 2 L][NH 2 (CH 3 ) 2 ] 2 $(DMF) 4 (H 2 O) 16 , was synthesized and structurally characterized. The compound possesses an anionic three-dimensional open framework and exhibits permanent porosity with selective gas adsorption of CO 2 over CH 4 . It exhibited strong fluorescence emission upon excitation at RT, and a selective, efficient emission quenching response towards nitroaromatic explosives. Experimental section Materials and methodsAll reagents and solvents were purchased from commercial sources and used without further purication. Ligand H 8 L was prepared as described in ref. 10.Infrared spectra were obtained on a Bruker Vector 22 spectrophotometer with KBr pellets in the 4000-400 cm À1 region. Elemental analyses for C, H, and N were performed on an Elementar Vario MICRO analyzer. Thermogravimetric analysis (TGA) was carried out in a Perkin-Elmer thermal analyzer under nitrogen with a heating rate of 10 C min À1 . Powder X-ray diffraction (PXRD) patterns were collected with a scan speed of Scheme 1 Schematic structure of H 8 L.

By using a rigid octadentenate carboxylate linker 5,5′,5″,5″′-silanetetrayltetraisophthalic acid (H8L), three new microporous coordination polymers, namely, [Cu4L(H2O)4]·2DMF·10H2O (1), [Zn5L2(H2O)4][NH2(CH3)2]6·2DMF·4H2O (2), and [Cd3(H2L)2][NH2(CH3)2]6·4DMF·14H2O (3), were solvothermally synthesized and structurally characterized. Compound 1 is a 3D framework built from a square paddlewheel [Cu2(O2CR)4] and a 8-connected cube L ligand to give a (4,8)-connected scu structure. Compound 2 is a 3D 4-nodal (4,4,4,8)-connected network with small 1D channels built on three tetrahedral Zn units and a 8-connecting ligand L. Compound 3 possesses a 3D structure with a (4,4,6)-connected net built on two tetrahedral Cd units and a 6-connecting ligand H2L6–. All the three compounds consist of large solvent accessible voids, but only compound 1 possesses permanent porosity as confirmed by N2, H2, O2, CO2 and CH4 gas adsorption measurements. Compounds 2 and 3 exhibited strong blue fluorescent emissions with a peak at 414 and 412 nm, respectively, at RT upon excitation owing to a ligand-centered excited state.

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