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[Display omitted] • A two-step cystine-mediated strategy is developed to alter the symmetry structure of C 3 N 4. • CN-25CYS possesses alkyl groups and nitrogen vacancies. • The distorted arrangements activate n-π* electron transition of carbon nitride. • The spatial separation of oxidation and reduction sites promotes charge separation. • CN-25CYS achieves 9.6-fold and 15.6-fold higher H 2 production rates and RhB degradation rates. The periodical distribution of N and C atoms in the carbon nitride skeleton results in intrinsically insufficient light absorption and serious carrier recombination. Herein, an efficient two-step cystine-mediated strategy was developed to alter the structure symmetry of C 3 N 4 via the introduction of alkyl groups and nitrogen vacancies. The experimental analysis and theoretical calculation confirm that the formation of alkyl groups and nitrogen vacancies can modulate band structure and activate n-π* electron transition. Especially, the charge density in CN-25CYS is redistributed with spatial separation of oxidation and reduction sites, suppressing photogenerated charge recombination effectively. Therefore, the distorted carbon nitride (CN-25CYS) exhibits 9.6-times and 15.6-times higher photoreaction rates in hydrogen production and RhB degradation than the pristine one (CN-0CYS), respectively. [ABSTRACT FROM AUTHOR]

[Display omitted] • Defective TEB-DBT CMPs with alkynyl defects via the molecular design are constructed. • Combination of the DFT calculations and experimental results, the incorporation of alkynyl defect accelerates the separation of photogenerated charge carriers. • The microstructure, band structure, and photocatalytic performance of CMPs can be regulated by varying the content of alkynyl defect. Defect engineering is a versatile approach to modulate band and electronic structures as well as materials performance. Nowadays, more research has been performed for enhancing catalytic performance of organic photocatalysts via the regulation of structure defect. Herein, we constructed the dibenzo[b,d]thiophene-sulfone-based conjugated microporous polymers (CMPs) with alkynyl defects via the molecular design. The effects of the concentration of alkynyl defects on the optical band gap, energy level structure, charge separation and photoactivity of the as-prepared samples were further explored. Combination of the first-principle density functional theory (DFT) calculations and experimental results, the incorporation of alkynyl defects accelerated the separation of photogenerated charge carriers. Furthermore, the concentration of alkynyl defects in CMPs can be adjusted by the dosage of 1,3-diethynylbenzene (MEB), thereby modulating the electronic structure and charge carrier separation properties. At appropriate alkynyl defect concentration, the prepared Defect-TD-2 shows higher visible-light photocatalytic performance for H 2 production and pollutants degradation. The work therefore shows an efficient self-modification strategy for improving the photoactivity of CMPs. [ABSTRACT FROM AUTHOR]

[Display omitted] • Au@Pt decorated Zn-CdS composites are fabricated for promoted charge separation. • Photodeposition leads to formation of Au-S bond and act as charge transfer channel. • The composites show synergetic effect of SPR and charge transfer channel. • Surface Pt serves active sites for rapid surface reaction. • Au@Pt/Zn-CdS exhibits lower charge transfer resistance and higher PEC activity. Photoelectrochemical (PEC) water splitting is a promising approach to solve the current energy and environmental crises. Herein, we developed a "one stone, two birds" strategy to construct Au@Pt decorated ZnO/CdS heterojunctions (ZCAP) with Au-S bond and surface plasmon resonance (SPR) effect for promoted PEC water splitting. The optimized ZCAP structure exhibited the highest photocurrent density of 4.23 mA/cm2 at 1.23 V vs. RHE and hydrogen evolution rate of 72.3 μmol·cm−2·h−1, which is magnitude higher than pure ZnO. In-depth investigations indicate that SPR effect can afford hot electrons, whereas Au-S bonds over interface act as transmission bridge for facilitated electron transfer, the synergy of them achieves efficient charge separation and light utilization. Meanwhile, surface Pt nanoparticles serve as active sites for rapid charge transfer and promoted surface reaction. This article illustrates that the synergy of SPR and electron transfer bridge is an efficient strategy for promoted PEC performance. [ABSTRACT FROM AUTHOR]

[Display omitted] • 1 wt%Pd/NiMoO 4 with different Pd dispersity were synthesized. • Hydrogen spillover process adjusts hydrogenation sites and acidic sites. • 56.3–84.1% yields of cyclopentanones were obtained over Pd/NiMoO 4 -Cl. • 65.4–85.2% yields of cyclopentanols were generated over Pd/NiMoO 4 -AC. • Adsorption configurations of reactants determine the reaction route. Upgrading bioderived furfurals (furfural, 5-hydroxymethylfurfural) to cyclopentanones (cyclopentanone, 3-hydroxymethylcyclopentanone) and cyclopentanols (cyclopentanol, 3-hydroxymethylcyclopentanol) is a representative bifunctional catalytic process in biomass conversion. Here, a class of Pd/NiMoO 4 catalysts (Pd/NiMoO 4 -Cl, Pd/NiMoO 4 -AC) with low Pd loading (1.0 wt%) and different Pd dispersion are synthesized. The hydrogenation active sites and acidic sites of catalysts were adjusted by a water-mediated hydrogen spillover process. 56.3–85.3% yields of cyclopentanones and 65.4–85.2% yields of cyclopentanols were obtained by hydrogenative ring-rearrangement route of furfurals over Pd/NiMoO 4 -Cl and Pd/NiMoO 4 -AC, respectively. Over-hydrogenated byproducts (tetrahydrofurfuryl alcohol, 2,5-bis(hydroxymethyl)tetrahydrofuran) with a yield above 54% were generated by a full hydrogenation route over Pd/C. The difference in catalytic performance is results from alteration of the adsorption configurations of reactants and the transformation of Lewis acid sites to Brønsted acid sites by hydrogen spillover. This work presents an effective strategy for governing reaction routes and enhancing bifunctional catalysis with a hydrogen spillover mechanism. [ABSTRACT FROM AUTHOR]