Excess carbon dioxide (CO ) emissions and their inevitable consequences continue to stimulate hard debate and awareness in both academic and public spaces, despite the widespread lack of understanding on what really is needed to capture and store the unwanted CO . Of the entire carbon capture and storage (CCS) operation, capture is the most costly process, consisting of nearly 70 % of the price tag. In this tutorial review, CO capture science and technology based on adsorbents are described and evaluated in the context of chemistry and methods, after briefly introducing the current status of CO emissions. An effective sorbent design is suggested, whereby six checkpoints are expected to be met: cost, capacity, selectivity, stability, recyclability, and fast kinetics.

Complex multiple-component semiconductor photocatalysts can be constructed that display enhanced catalytic efficiency via multiple charge and energy transfer, mimicking photosystems in nature. In contrast, the efficiency of single-component semiconductor photocatalysts is usually limited due to the fast recombination of the photogenerated excitons. Here, we report the design of an asymmetric covalent triazine framework as an efficient organic single-component semiconductor photocatalyst. Four different molecular donor-acceptor domains are obtained within the network, leading to enhanced photogenerated charge separation via an intramolecular energy transfer cascade. The photocatalytic efficiency of the asymmetric covalent triazine framework is superior to that of its symmetric counterparts; this was demonstrated by the visible-light-driven formation of benzophosphole oxides from diphenylphosphine oxide and diphenylacetylene.

Carbon dioxide capture and separation requires robust solids that can stand harsh environments where a hot mixture of gases is often found. Herein, the fi rst and comprehensive syntheses of porous sulfur-bridged covalent organic polymers (COPs) and their application for carbon dioxide capture in warm conditions and a wide range of pressures (0-200 bar) are reported. These COPs can store up to 3294 mg g − 1 of carbon dioxide at 318 K and 200 bar while being highly stable against heating up to 400 ° C. The carbon dioxide capacity of the COPs is also not hindered upon boiling in water for at least one week. Physisorptive binding is prevalent with isosteric heat of adsorptions around 24 kJ mol − 1 . M06-2X and RIMP2 calculations yield the same relative trend of binding energies, where, interestingly, the dimer of triazine and benzene play a cooperative role for a stronger binding of CO 2 (19.2 kJ mol − 1 ) as compared to a separate binding with triazine (13.3 kJ mol − 1 ) or benzene (11.8 kJ mol − 1 ).

Visible-light-driven chemical transformations via photocatalysis have witnessed an explosive growth in the past decade, accompanying the enormous development of the photocatalyst design. Among the intensely investigated systems, molecular photocatalysts as transition-metal complexes and conjugated organic dyes have been established as efficient homogeneous photocatalytic systems for organic photoredox reactions. Nonetheless, heterogeneous photocatalysts possess considerable advantages such as being highly stable, easily separable, and reusable. Especially, the organic, macromolecular heterogeneous photocatalysts have emerged as a nontoxic and potentially more environmentally friendly alternative to the traditional catalytic systems. Among them, poly(benzothiadiazoles) and their derivatives have demonstrated the ability to catalyze various organic photoredox reactions under visible-light irradiation. In this Review, the recent development of metal-free and heterogeneous photocatalytic systems based on poly(benzothiadiazoles) and their derivatives is summarized. An overview of organic photoredox reactions mediated via radicals obtained from the photogenerated electron and hole of the photocatalysts is given, and the underlying mechanisms of photochemical transformations are illuminated. The structural design principles of poly(benzothiadiazoles) for targeted photoredox reactions are also discussed.

A review on the recent developments in controlling the structural, photophysical and electronic properties of conjugated porous polymer (CPP) photocatalysts is presented.