SiO2/P25 (SP) composites doped with different contents of cerium were prepared by a hydrothermal process at a relatively low temperature in this experiment. The resulting Ce–SiO2/P25 (CSP) composites were successfully characterized by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM), high resolution transmission electron microscopy (HRTEM), N2-physisorption, UV-vis diffuse reflectance spectroscopy (DRS), and photoluminescence spectroscopy (PL). The photocatalytic activities of the as-obtained catalysts were evaluated for the degradation of organic dyes, including Methylene Blue (MB) and Reactive Red 4 (RR4), under visible-light irradiation. The best results were obtained for a cerium loading of 5 mM. The CSP-5 nanoparticle showed the 91.8% decomposition of MB and 90.2% decomposition of RR4 in the liquid phase at room temperature under visible-light irradiation in a photoreactor, and the corresponding hydrogen evolution rate was 2.315 mmol g−1, which was more efficient than that of pristine P25. Remarkably enhanced activities towards the photodecomposition of several organic compounds were observed depending on the synergistic effect between silicon and cerium. The Ce–SiO2/P25 structure leads to efficient light harvesting into the visible-light region by forming new energy levels inside the nanoparticles and then electron–hole recombination could be effectively inhibited. The BET surface area measurement was used to provide an insight into the enhanced photocatalytic activity of the CSP composites, which was also understood to be because of the relative enhancement of the adsorption of organic molecules on the photocatalyst surface. In addition, the effect of the initial pH values on the photocatalytic degradation of different dyes using CSP-5 was investigated. Finally, a good recyclability of CSP-5 was demonstrated compared to that of pristine P25. Herein, the photocatalytic mechanism has been concretely explained.

In this investigation, the two-dimensional (2D) self-assembly nanostructures of a series of cyclic oligo(phenylene-ethynylene) (OPE) molecules (L1, L2-6 and L2-12) at the 1-phenyloctane/highly oriented pyrolytic graphite (HOPG) interface were thoroughly studied using scanning tunneling microscopy (STM). Comparative STM studies with their triangular Pt(II) diimine complexes (C1, C2-6 and C2-12) were also carried out. Based on careful measurements on single molecule level STM images and density functional theory (DFT) calculations, the formation mechanisms of the nanoarrays formed were revealed.

In the present investigation, we reported the fabrication of a chicken-wire porous 2D network formed by triphenylene-2,6,10-tricarboxylic acid (H3TTCA) at the liquid–solid interface. When coronene (COR) molecules were added into the system, the H3TTCA honey-comb network was broken and the reconstructed structures of the H3TTCA/COR host–guest systems were subsequently formed. Scanning tunneling microscopic (STM) measurements and density function theory (DFT) calculations were utilized to reveal the structural variety in the co-assembly of H3TTCA/COR controlled by the solution concentration at 1-heptanoic acid/HOPG interface.

Efficient photochemical reactions on a surface are of great importance for their potential applications in optoelectronic devices. In this work, a highly efficient photodimerization reaction of an olefin cocrystal built from two trans-1,2-bis(4-pyridyl)ethylenes (4,4′-bpe) and two isophthalic acid molecules via N⋯H–O hydrogen bonds in between was achieved in a nanotemplate on a highly oriented pyrolytic graphite (HOPG) surface. 4,4′-Bpe molecules first undergo the trans–cis isomerization followed by [2+2] photodimerization in the nanotemplate on HOPG upon UV irradiation. The efficiency of the isomerization as well as the photodimerization in the presence of the nanotemplate is much higher than that in its absence. These results provide a facile way to achieve highly efficient photodimerization of olefins on a large scale on surfaces.

Nanoscaled two-dimensional (2D) chiral architectures are increasingly receiving scientific interest, because of their potential applications in many domains. In this paper, we present a new method for constructing 2D chiral architectures on surface. Based on in situ Schiff-base reaction of achiral dialdehyde with two types of achiral amines at the solid/liquid interface, two chiral species have been directly formed and confirmed by means of a scanning tunneling microscopy (STM) technique. This work introduces a novel strategy to construct 2D surface chirality, which might be applied in fabricating functional films and nanoelectronic devices.Keywords: chirality; nanoflower; Schiff-base reaction; self-assembly; STM; two-dimensional;

•Photocataysts were employed to decolorize both cationic MB and anionic RR4 dye respectively.•Degradation efficiency and hydrogen evolution rate was over 90% and 2.44 mmol g−1 respectively.•Removal efficiency by In/C-P25 was sustainable and stable after 5 times of repeated usage.•The effects of initial pH values on MB and RR4 solution for photocatalysts was investigated.The commercially available TiO2 Degussa P25 was modified using a simple technique to produce a visible-light-actived indium and carbon doped P25 catalyst. The modified photocatalysts have been successfully obtained by thermal heating method. These as-obtained products were successfully characterized by X-ray diffraction (XRD), X-ray photoelectrion spectroscopy (XPS), scanning electron microscope (SEM), high resolution transmission electron microscopy (HRTEM), UV–vis diffuse reflectance spectroscopy (DRS) and photoluminescence (PL) spectroscopy respectively. The photocatalytic activities of all prepared catalysts were evaluated by the degradation of organic dyes including methylene blue (MB) and Reactive Red 4 (RR4) under visible light irradiation. As the result shown, the indium and carbon co-doped on P25 nanocomposites possessed the extended light absorption in visible light and better charge separation capability as compared to the pristine P25. The optimum loading of In3+ ions on P25 was 15%. Moreover, 15% In2O3/C-P25 showed the highest degradation rate of organic dye, which the removal efficiency can reach over 90% after 90 min and the corresponding hydrogen evolution rate of 15% In2O3/C-P25 was 9 times than P25. It was concluded that the synergistic effects of In3+ ions and carbon narrowed the band gap of TiO2 and promoted charge separation, which played a significant role for the enhancement of photoactivity. In addition, it was observed that the photo-degradation for all catalysts followed the first order reaction kinetics. Furthermore, the influence of initial pH values on the photocatalytic degradation of MB and RR4 using 15% In2O3/C-P25 catalyst was also investigated. Finally, the stability test of photocatalysts was carried out and the photocatalytic mechanism was explained concretely.

Efficient photochemical reactions on a surface are of great importance for their potential applications in optoelectronic devices. In this work, a highly efficient photodimerization reaction of an olefin cocrystal built from two trans-1,2-bis(4-pyridyl)ethylenes (4,4′-bpe) and two isophthalic acid molecules via N⋯H–O hydrogen bonds in between was achieved in a nanotemplate on a highly oriented pyrolytic graphite (HOPG) surface. 4,4′-Bpe molecules first undergo the trans–cis isomerization followed by [2+2] photodimerization in the nanotemplate on HOPG upon UV irradiation. The efficiency of the isomerization as well as the photodimerization in the presence of the nanotemplate is much higher than that in its absence. These results provide a facile way to achieve highly efficient photodimerization of olefins on a large scale on surfaces.

In the present investigation, we reported the fabrication of a chicken-wire porous 2D network formed by triphenylene-2,6,10-tricarboxylic acid (H3TTCA) at the liquid–solid interface. When coronene (COR) molecules were added into the system, the H3TTCA honey-comb network was broken and the reconstructed structures of the H3TTCA/COR host–guest systems were subsequently formed. Scanning tunneling microscopic (STM) measurements and density function theory (DFT) calculations were utilized to reveal the structural variety in the co-assembly of H3TTCA/COR controlled by the solution concentration at 1-heptanoic acid/HOPG interface.

The nanostructures of a series of conjugated oligo(p-phenylene-ethynylene)s (OPE) adsorbed on a surface were thoroughly studied using scanning tunneling microscopy (STM). These oligomers have different backbone lengths and side chains. As a result, various nanostructures displaying periodic linear patterns at a single molecule level were obtained. Based on careful measurements on the STM images in combination with density functional theory (DFT) calculations, it could be found that the vertical and parallel distances between neighboring oligomers were responsible for the specific arrangement of the backbone and side chains. The results showed that these molecular designs strongly affect their self-assembled structure, which is important to clarify the structure–property relationship in the nanoscience field.