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Photocatalytic CO2 reduction offers a promising approach for managing global carbon balance. The smooth delivery of the photoexcited electrons to the active sites without the extra photosensitizers is still challenging. Herein, a series of donor-π-acceptor conjugated organic polymers (COPs) were produced using anthracene, cobalt-coordinated bipyridyl, and benzene as donor, acceptor, and π linker units, respectively. The introduction of phenyl linker significantly improved the activities of photocatalytic CO2 reduction upon visible light illumination. Structure-performance relationship examinations uncovered that donor-π-acceptor structure promotes mobility of charge carriers and utilization efficiency on the catalytically active sites, resulting in high photocatalytic activity and durability for CO2 photoreduction. The in-depth insights into the electron transport processes open new perspectives for further optimization and rational design of photoactive polymers with high efficiency for solar-energy conversion.

Photocatalytic CO2 reduction is a promising technology to mitigate environmental issue and the energy crisis. The four nitrogen atoms in the porphyrin ring can incorporate transition metals to form stable active sites for CO2 activation and photoreduction. Nevertheless, the photocatalytic efficiency of metalloporphyrins is still low due to the insufficient photoelectron injection to drive CO2 photoreduction upon visible light irradiation. To address this issue, considerable efforts have been made to introduce photosensitizers for constructing homogeneous or heterogeneous metalloporphyrin-based photocatalytic systems. In this Review, recent advances of metalloporphyrin-based materials for visible-light-driven CO2 reduction were summarized. The methods for the modulation of photosensitizing process at molecular level were presented for the promotion of photocatalytic performance. The mechanism of CO2 activation and photocatalytic conversion was illustrated. Better insight into the structure-activity relationship provides guidance to the design of metalloporphyrin-related photocatalytic systems.

It is of great significance to mediate the redox kinetics and shuttle effect of polysulfides in pursuit of high-energy-density and long-life lithium-sulfur (Li-S) batteries. Herein, a new strategy is proposed based on the electrostatic attraction and catalytic effect of polysulfides for the modification of the polypropylene (PP) separator. Guanidinium-based ionic-covalent organic nanosheets (iCON) on the surface of Ti3 C2 is presented as a coating layer for the PP separator. The synergetic effects of Ti3 C2 and iCON provide new platforms to suppress the shuttle effect of polysulfides, expedite the redox kinetics of sulfur species, and promote efficient conversion of the intercepted polysulfides. The functional separator endows carbon nanotube/sulfur cathodes with excellent electrochemical performance. The average capacity decay per cycle within 2000 cycles at 2 C is as low as 0.006%. The separator is even effective in the case of sulfur content of 90 wt% and sulfur loading of 7.6 mg cm-2 ; the reversible capacity, areal capacity, and volumetric capacity at 0.1 C are as high as 1186 mA h g-1 , 9.01 mA h cm-2 , and 1201 mA h cm-3 , respectively. This work provides a promising approach toward separator modification for the development of high-performance Li-S batteries.

Artificial transistors represent an ideal means for meeting the requirements in interfacing with biological systems. It is pivotal to develop new proton-conductive materials for the transduction between biochemical events and electronic signals. Herein, the first demonstration of a porous organic polymer membrane (POPM) as a proton-conductive material for protonic field-effect transistors is presented. The POPM is readily prepared through a thiourea-formation condensation reaction. Under hydrated conditions and at room temperature, the POPM delivers a proton mobility of 5.7 × 10-3 cm2 V-1 s-1 ; the charge carrier densities are successfully modulated from 4.3 × 1017 to 14.1 × 1017 cm-3 by the gate voltage. This study provides a type of promising modular proton-conductive materials for bioelectronics application.