Rong-Xun Li

Amine-Tethered Adsorbents Based on Three-Dimensional Macroporous Silica for CO2 Capture from Simulated Flue Gas and Air

New covalently tethered CO2 adsorbents are synthesized through the in situ polymerization of N-carboxyanhydride (NCA) of l-alanine from amine-functionalized three-dimensional (3D) interconnected macroporous silica (MPS). The interconnected macropores provide low-resistant pathways for the diffusion of CO2 molecules, while the abundant mesopores ensure the high pore volume. The adsorbents exhibit high molecular weight (of up to 13058 Da), high amine loading (more than 10.98 mmol N g(-1)), fast CO2 capture kinetics (t1/2 < 1 min), high adsorption capacity (of up to 3.86 mmol CO2 g(-1) in simulated flue gas and 2.65 mmol CO2 g(-1) in simulated ambient air under 1 atm of dry CO2), as well as good stability over 120 adsorption-desorption cycles, which allows the overall CO2 capture process to be promising and sustainable.

Synthesis, characterization, and high temperature CO2 capture of new CaO based hollow sphere sorbents

New mesoscopic hollow sphere sorbents composed of CaO/Ca12Al14O33 with tunable cavity size are successfully synthesized using sulfonated polystyrene (PS) as hard template. The monodispersed hollow nanostructure provides the void space that can buffer against the large volume change during the carbonation/calcination cycles. The as-prepared high temperature CO2 sorbents have large specific surface areas, fast adsorption kinetics, significantly improved CO2 adsorption capacity and cyclic reaction stability. This method opens up new opportunities in the development of high performance next-generation high temperature CO2 sorbents.

Covalent grafting of polyethyleneimine on hydroxylated three-dimensional graphene for superior CO2 capture

Covalently tethered CO2 adsorbents are synthesized by acid catalyzed ring-opening polymerization of aziridine on the basal planes of three-dimensional hydroxylated graphene (HG). The resulting materials possess high surface areas, strong covalent bonds between polyethyleneimine (PEI) and graphene, and high thermal conductivity. The HG–PEI nanocomposites exhibit high amine loading (more than 10.03 mmol N g−1), high adsorption capacity (up to 4.13 mmol CO2 g−1 in simulated ambient air under 1 atm of dry CO2) as well as good stability both at low (100 °C) and high desorption temperatures (135 °C), which allows the overall CO2 capture process to be promising and sustainable.

A three-dimensional conducting oxide hollow nanobead photoanode: synthesis, characterization, and applications in dye-sensitized solar cells

It was reported that liquid-electrolyte-based dye-sensitized solar cells (DSSCs) are “majority carrier” devices where the internal electric field is screened off; accordingly, the electrons travel through the TiO2 nanoparticles by diffusion rather than drift, resulting in “sticky” electrons which undergo frequent trapping and detrapping. We report here the drift transport observed in I−/I3− electrolyte-based DSSCs by using a 3-dimensional (3-D) transparent conducting oxide (TCO) such as fluorinated tin oxide (FTO) coated with TiO2 as the photoanode. By re-allocating the charge transport process, the thin TiO2 layer (20–30 nm) covering the entire TCO scaffold leads to a striking reduction in charge transport distance by a factor of 102 to 103. Electrochemical impedance spectroscopy (EIS) study indicates that it is viable to establish a potential gradient in the 3-D TCO scaffold; thus, the electron transport in this 3-D TCO structure exhibits field-driven drift behaviour, which is verified by the linear dependence of electron lifetime on the photovoltage, along with the virtual independence of electron transport resistance with respect to the bias voltage in spite of the use of the liquid I−/I3− electrolyte.

Tetrakis(1-ethyl-1H-imidazole-κN3)diisothiocyanatocobalt(II)

# 2006 International Union of Crystallography All rights reserved The structure of the title compound, [Co(NCS)2(C5H8N2)4], consists of isolated molecules of [Co(NCS)2(Eim)4] (Eim = 1ethylimidazole), having an octahedral CoN6 configuration. The NCS anions are positioned in a trans-configuration and four N atoms from the 1-ethylimidazole ligands define the equatorial plane. The mean Co—N(Eim) and Co—N(NCS) distances are 2.137 (6) and 2.152 (6) Å respectively.