In view of the limited ruthenium resource, metal-free organic dyes may play a prominent role in the coming large-scale application of cost-effective dye-sensitized solar cells, if their efficiency and stability can be considerably improved. In this paper we utilized a binary π-conjugated spacer of ethylenedioxythiophene and dithienosilole to construct a high molar absorption coefficient push-pull dye, characteristic of an intramolecular charge-transfer band peaking at 584 nm measured in chloroform. In comparison with the standard ruthenium sensitizer Z907, this metal-free chromophore C219 endowed a nanocrystalline titania film with an evident light-harvesting enhancement, leading to an unprecedented 10.0-10.3% efficiency at the AM1.5G conditions for dyesensitized solar cells with nonruthenium dyestuffs, although a highly volatile electrolyte was used. Transient absorption measurements have revealed that even if the kinetics of back-electron transfer and dye regeneration are considerably different for Z907 and C219, the branching ratios of these two charge-transfer channels are over 35 for both dyes, ensuring a high yield of net charge separation at the titania/dye/electrolyte interface. A solvent-free ionic liquid cell with C219 as the sensitizer exhibited an impressive efficiency of 8.9% under a low light intensity of 14.39 mW cm -2 , making it very favorable for the indoor application of flexible dye-sensitized solar cells.

A consolidated ionothermal strategy was developed for the polymerization of thermally unstable nitriles to construct high performance materials with permanent porosity, and carbazole, dibenzofuran, and dibenzothiophene were separately introduced into covalent triazine-based networks to investigate the effects of heterocycles on the gas adsorption performance. Three nitriles, namely 3,6-dicyanocarbazole, 3,6-dicyanodibenzofuran, and 3,6-dicyanodibenzothiophene, were designed and synthesized, which were readily converted to heat-resistant intermediates at a moderate temperature and then polymerized to create highly porous poly(triazine) networks instead of the traditional one-step procedure. This documents an improved strategy for the successful construction of heterocyclic-functional triazine-based materials. The chemical structures of monomers and polymers were confirmed by 1 H NMR, FTIR, and elemental analysis. Such polymers with high physical−chemical stability and comparable BET surface areas can uptake 1.44 wt % H 2 at 77 K/1 bar and 14.0 wt % CO 2 at 273 K/1 bar and present a high selectivity for gas adsorption of CO 2 (CO 2 /N 2 ideal selectivity up to 45 at 273K/1.0 bar). The nitrogen-and oxygen-rich characteristics of carbazole and dibenzofuran feature the networks strong affinity for CO 2 and thereby high CO 2 adsorption capacity. This also helps to thoroughly understand the influence of pore structure and chemical composition on the adsorption properties of small gas molecules.

Two new alternating low bandgap copolymers from benzodithiophene and benzotriazole units, namely poly{4,8-bis(2-ethylhexyloxy)benzo [1,2-b; 3,4-b]dithiophene-2,6-diyl-alt-2-octyl-4,7di(thiophen-2-yl)-2H-benzo [d][1,2,3]triazole-5 0 ,5 00 -diyl} (PBDTDTBTz) and poly{4,8-bis(2ethylhexyloxy)benzo [1,2-b;3,4-b]dithiophene-2,6-diyl-alt-2-dodecylbenzotriazole-4,7-diyl} (PBDTBTz), were designed and synthesized by a typical Stille coupling polymerization method. The copolymers were characterized by thermogravimetric analysis, UV-vis absorption and cyclic voltammetry. PBDTDTBTz and PBDTBTz possess moderate molecular weights and excellent thermal properties with a 5% weight loss temperatures (T d ) around 300 C. They exhibited good optical absorption, with peaks at 527 nm and 562 nm in the film state, respectively. Photovoltaic properties of the copolymers blended with [6,6]-phenyl-C61-butyric acid methyl ester (PC 61 BM) or [6,6]-phenyl-C71-butyric acid methyl ester (PC 71 BM) as electron acceptors, were investigated. The photovoltaic device with the PBDTDTBTz/PC 71 BM shows a power conversion efficiency of 1.7% with a short circuit current density of 4.5 mA cm À2 and a good fill factor of 0.62, while PBDTBTz demonstrated a moderate power conversion efficiency of up to 1.4%, under the illumination of AM 1.5, 100 mW cm À2 with a device structure of ITO/PEDOT: PSS/polymer: PC 71 BM (1 : 4)/Ca/Al. All the above information highlighted that this kind of the copolymers is promising for the application of polymer solar cells.

The advent of microporous organic polymers (MOPs) has delivered great potential in gas storage and separation (CCS). However, the presence of only micropores in these polymers often imposes diffusion limitations, which has resulted in the low utilization of MOPs in CCS. Herein, facile chemical activation of the single microporous organic polymers (MOPs) resulted in a series of hierarchically porous carbons with hierarchically meso-microporous structures and high CO2 uptake capacities at low pressures. The MOPs precursors (termed as MOP-7-10) with a simple narrow micropore structure obtained in this work possess moderate apparent BET surface areas ranging from 479 to 819 m(2) g(-1). By comparing different activating agents for the carbonization of these MOPs matrials, we found the optimized carbon matrials MOPs-C activated by KOH show unique hierarchically porous structures with a significant expansion of dominant pore size from micropores to mesopores, whereas their microporosity is also significantly improved, which was evidenced by a significant increase in the micropore volume (from 0.27 to 0.68 cm(3) g(-1)). This maybe related to the collapse and the structural rearrangement of the polymer farmeworks resulted from the activation of the activating agent KOH at high temperature. The as-made hierarchically porous carbons MOPs-C show an obvious increase in the BET surface area (from 819 to 1824 m(2) g(-1)). And the unique hierarchically porous structures of MOPs-C significantly contributed to the enhancement of the CO2 capture capacities, which are up to 214 mg g(-1) (at 273 K and 1 bar) and 52 mg g(-1) (at 273 K and 0.15 bar), superior to those of the most known MOPs and porous carbons. The high physicochemical stabilities and appropriate isosteric adsorption heats as well as high CO2/N2 ideal selectivities endow these hierarchically porous carbon materials great potential in gas sorption and separation.

Rich heteroatom-doped conjugated nanoporous polymers with uniform microspherical morphology exhibit remarkably high capacity up to 450 wt% for removing iodine from the vapor phase (at 348 K and atmospheric pressure).