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In this study, mung bean-based nanoporous activated carbons with different pore properties were prepared by varying the mass ratio of activating agent (KOH) and activation temperature. The low-temperature nitrogen adsorption analysis was used to characterize the effect of the KOH ratios and the activation temperatures on the textural properties and surface heterogeneity. The prepared ACs were further used to measure the adsorption capacity of CO2, CH4, and N2. We found that the adsorption amounts were highly dependent on the ultra-micropore volume (VD<0.8nm) rather than the surface area. Their adsorption characteristics were well explained by the polarizability and the adsorption energy distribution. The experimental adsorption isotherm data were well fitted to the Sips equation. The ideal adsorbed solution theory (IAST) was further applied to predict the adsorption selectivity of binary mixtures CO2/N2, CO2/CH4, and CH4/N2 at 25 °C. [ABSTRACT FROM AUTHOR]

In this study, mung bean-based nanoporous activated carbons with different pore properties were prepared by varying the mass ratio of activating agent (KOH) and activation temperature. The low-temperature nitrogen adsorption analysis was used to characterize the effect of the KOH ratios and the activation temperatures on the textural properties and surface heterogeneity. The prepared ACs were further used to measure the adsorption capacity of CO2, CH4, and N2. We found that the adsorption amounts were highly dependent on the ultra-micropore volume (VD<0.8nm) rather than the surface area. Their adsorption characteristics were well explained by the polarizability and the adsorption energy distribution. The experimental adsorption isotherm data were well fitted to the Sips equation. The ideal adsorbed solution theory (IAST) was further applied to predict the adsorption selectivity of binary mixtures CO2/N2, CO2/CH4, and CH4/N2 at 25 °C. [ABSTRACT FROM AUTHOR]

Hollow SnO2 microstructures (HSM) with a mesoporous surface have been simply fabricated by a template impregnation technique using Ceiba pentandra (L.) Gaertn. (kapok) as a natural template. The HSM could be used as an efficient photocatalyst for methylene blue dye photodegradation. [ABSTRACT FROM AUTHOR]

The adsorption mechanism for the N719 dye on a TiO2 electrode was examined by the kinetic and diffusion models (pseudo-first order, pseudo-second order, and intra-particle diffusion models). Among these methods, the observed adsorption kinetics are well-described using the pseudo-second order model. Moreover, the film diffusion process was the main controlling step of adsorption, which was analysed using a diffusion-based model. The photodynamic properties in dye-sensitized solar cells (DSSCs) were investigated using time-resolved transient absorption techniques. The photodynamics of the oxidized N719 species were shown to be dependent on the adsorption time, and also the adsorbed concentration of N719. The photovoltaic parameters (Jsc, Voc, FF and η) of this DSSC were determined in terms of the dye adsorption amounts. The solar cell performance correlates significantly with charge recombination and dye regeneration dynamics, which are also affected by the dye adsorption amounts. Therefore, the photovoltaic performance of this DSSC can be interpreted in terms of the adsorption kinetics and the photodynamics of oxidized N719. [ABSTRACT FROM AUTHOR]

In this work, we have investigated the light-penetration and light-scattering effects in a dye-sensitised solar cell (DSSC) that consists of a bilayer structure of normal and light-scattering layers (LSLs). The LSL is located at the backside of the DSSC to reflect light. The photovoltaic performance of the LSL-DSSC is improved by the light reflection from the layer, which significantly increases the reabsorbing ability of the dye. However, the intensity of the penetrated light was reduced when the concentration of the adsorbed dye was increased, indicating that light scattering and light penetration are hindered by the adsorbed dye. In order to obtain a relatively inexpensive, but highly efficient DSSC, the relationship between the dye concentration and the conversion efficiency was investigated to maximise the light-scattering effect using a minimal amount of adsorbed dye. [ABSTRACT FROM AUTHOR]

Nanocrystalline TiO2 particles were prepared via the sol–gel process. The particle size and nanostructure of the TiO2 sol were controlled through the ageing process accompanied by hydrolysis–polycondensation. The resultant TiO2 particles were analysed by BET, HR-TEM, PSA, TGA, turbidity, XRD, and zeta potential analyses. The TiO2 size increased with increasing ageing time and reaction temperature. A phase transformation from anatase to rutile occurred with heat treatment at 500 °C. The phase transformation is strongly influenced by the primary particle sizes of TiO2, which were characterised via XRD and Raman spectroscopic analyses. [ABSTRACT FROM AUTHOR]

Nanoporous TiO2 (NP-TiO2) was synthesized using different mesostructured silica templates such as SBA-15, KIT-6, and MSU-H, which have highly ordered pore or well-connected inner-network structures. NP-TiO2 has a large surface area and a dye-adsorption capability 1.5 times greater than that of nanocrystalline TiO2 (NC-TiO2). We have investigated dye-sensitized solar cells (DSSCs) with bilayer TiO2 electrodes, which were prepared by applying a coating of NP-TiO2 onto an NC-TiO2 film. The photocurrent (Jsc) and fill factor (FF) for the DSSC with the bilayer TiO2 electrode were greatly improved. The solar energy conversion efficiency (ηeff) also increased over 15% compared with a DSSC with a monolayer NC-TiO2 electrode. For the DSSC with the bilayer TiO2 electrode, the charge recombination and dye-regeneration processes, which were studied by transient absorption spectroscopy, were slower and faster, respectively, than those of the DSSC with an NC-TiO2 electrode. [ABSTRACT FROM AUTHOR]

Correction for ‘Dye adsorption mechanisms in TiO2 films, and their effects on the photodynamic and photovoltaic properties in dye-sensitized solar cells’ by Kyung-Jun Hwang et al., Phys. Chem. Chem. Phys., 2015, 17, 21974–21981. [ABSTRACT FROM AUTHOR]

Correction for ‘Light-penetration and light-scattering effects in dye-sensitised solar cells’ by Kyung-Jun Hwang et al., New J. Chem., 2014, 38, 6161–6167. [ABSTRACT FROM AUTHOR]