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[Display omitted] • Selective oxidation of benzylic C H bonds is achieved using O 2 under visible light. • MIL-125(Ti)/PMTPA composite with optimal composition has excellent photocatalytic activity. • The heterojunction structure improves the efficiency of the conversion of holes into reaction intermediates. • The type I heterojunction structure favors the transfer of electrons and holes to the interface. Selective oxidation of saturated C H bonds to value-added chemicals under mild conditions is of great importance in chemical community. In this work, conjugated polymer (PMPTA) coated MIL-125(Ti) composites with type I heterojunction structure were obtained from the mixture of MIL-125(Ti), melamine and terephthalaldehyde via a solvent-free hydrothermal method. The MP-30 with optimal composition has excellent photocatalytic activity for the selective oxidation of benzylic C H bonds to their corresponding aldehydes and ketones under the illumination of 420 nm light using O 2 as oxidant and N-Hydroxyphthalimide (NHPI) as co-catalyst. The conversions of fluorene catalyzed by MIL-125(Ti) and PMTPA are 32% and 65%, respectively, while the conversions of fluorene over MP-20, MP-30 and MP-40 are significantly improved, which are 86%, 99% and 77%, respectively. The characterization results from photoluminescence spectroscopy, photocurrent and band gap positions demonstrate that the one-way transfer of electrons and holes between the MIL-125(Ti) and PMTPA through the heterojunction structure allows the substrate to react rapidly on the outer layer of heterostructured MIL-125(Ti)/PMTPA, resulting an increase in photocatalytic efficiency. Moreover, the introduced heterojunction structure reduces the recombination of photo-generated electrons and holes and improves the efficiency of the conversion of holes into reaction intermediates. [ABSTRACT FROM AUTHOR]

Encapsulation of TiO 2 nanobelts into crystalline and porous covalent organic frameworks materials to form a core-shell structure can enhance reactivity, selectivity and durability of photocatalysts distinctly. In this work, a range of TiO 2 nanobelts@COF nanocomposites with different thicknesses of COF shell were fabricated via a novel and facile seed growth method. The results of photooxidation of benzyl alcohol under visible light (> 420 nm) showed that TiO 2 @COF-3 with COF shell thickness of around 15 nm showed the highest conversion (92.5%) with the maximum rate constant (6.73 × 10−2 h−1), which is approximately 10.1 times as that of TiO 2 and 12.9 times as that of COF. The enhanced photocatalytic activity of hybrid materials was mainly owing to the improved photon adsorption ability and charge carriers transfer from COF to TiO 2. In addition, TiO 2 @COF-3 still showed relatively high stability after 5 cycles under the same reaction condition. Therefore, this type of hybrid photocatalysts possesses great potentials in future green organic synthesis. • Core-shell TiO 2 @COF hybrids are synthesized by a seed growth method. • The COFs materials show as an excellent light-harvest materials. • The covalent-bond connection promotes the charge-carrier transfer and separation. • TiO 2 @COF-3 shows high activity and stability in photooxidation of aromatic alcohols. • TiO 2 @COF hybrids are firstly applied to the photooxidation of aromatic alcohol. [ABSTRACT FROM AUTHOR]

CDs are applied in the enhancement of EL of Poly (9-vinyl carbazole) with the increased brightness by 54.3 %. [Display omitted] • CDs are applied in the enhancement of EL of PVK with increased brightness by 54.3 %. • The CDs enhanced PVK LEDs possess the EL wavelength of 432 nm. • The CIE coordinates of CDs enhanced PVK LEDs are at (0.17, 0.10) with the brightness of 176 cd m−2. • The mechanisms of charge transport between CDs and PVK are determined by TPV and method of EMD. Carbon dots (CDs) are one species of multifunctionally auxiliary materials with promising application in photoelectrocatalyst and photoelectrodevices. However, there are few reports on enhancing the electroluminescence (EL) of materials by CDs and the effects of CDs on the charge transport dynamics have not been revealed so far. Herein, CDs are firstly successful to be applied in the enhancement of EL of Poly (9-vinyl carbazole), which is set as model material for research, abbreviated as PVK with the EL wavelength of 432 nm. The brightness of CDs enhanced PVK LEDs reaches 176 cd m−2 that obviously 54.3 % higher than that of pure PVK based LEDs and other parameters are all improved. The Commission Internationale d'Eclairage coordinates of CDs enhanced PVK LEDs are situated at (0.17, 0.10). Notably, through the transient photovoltage technology and method of empirical mode decomposition, the mechanisms of charge transport dynamics between CDs and PVK molecules are determined. This work paves a new direction for the improvement of the luminescent properties of electroluminescent devices and a new mentality to understand the effects of CDs on charge transport in the EL process. [ABSTRACT FROM AUTHOR]

Under AM 1.5 G light intensity, the photocurrent density of TCN-1.5 is 4.06 mA cm−2 at 1.23V vs RHE in 1.0 M NaOH, which is ca. 2.08 times higher than that of the pristine TiO 2. Besides, the in-situ TPV technology and its curve extrapolation analysis show the improvement of J abs , η sep and η inj caused by changes of morphology and structure, and the product of the three factors above perfectly correspond to the increase in photocurrent density. [Display omitted] • TiO 2 photoanode modified by C, N co-doping achieves efficient PEC performance. • The photocurrent density of TCN-1.5 is 4.06 mA cm−2 in 1 M NaOH under AM 1.5 G. • The efficiencies' improvement in PEC process was tested by in-situ TPV technology. • A new in-situ method for PEC material design and fabrication is provided. Photoelectrocatalysis (PEC) is one of the most important green energy conversion technologies. During the development of PEC, the J abs , η sep and η inj are challenges that hinder the performance enhancement of different kinds of photoanodes in PEC systems. As a stable, cheap and non-toxic PEC material, TiO 2 is also limited by the above challenges. Here, a series of C, N co-doped TiO 2 photoanodes were synthesized by hydrothermal method combined with a simple one-step thermal diffusion treatment. Under AM 1.5 G light intensity, the PEC performance of TCN-1.5 is 4.06 mA cm−2 at 1.23 V vs RHE in 1.0 M NaOH, which is ca. 2.08 times as high as the photocurrent density of the pristine TiO 2. Especially, an in-situ transient photoinduced voltage (TPV) method was developed to measure the changes on efficiencies mentioned above: J abs , η sep and η inj are improved by about 9.8 %, 24.9 % and 48.3 %, respectively, and their product is equal to the increase of photocurrent density. This work analyzes the improvement of efficiencies in the PEC process through in-situ characterization and opens up a new way for PEC material design and fabrication. [ABSTRACT FROM AUTHOR]

This paper presents controllable growth and photocatalytic activity of TiO 2 hierarchical nanostructures by solvothermal method at different temperatures. It is revealed by scanning electron microscopy (SEM) and transmission electron microscopy (TEM) that the morphology of TiO 2 can be effectively controlled as rose-like, chrysanthemum-like and sea-urchin-like only changing solvothermal temperature. BET surface area analysis confirms the presence of a mesoporous network in all the nanostructures, and shows high surface area at relatively high temperature. The photocatalytic activities of the photocatalysts are evaluated by the photodegradation of RhB under UV light irradiation. The TiO 2 samples exhibit high activity on the photodegradation of RhB, which is higher than that of the commercial P25. The enhancement in photocatalytic performance can be attributed to the synergetic effect of the surface area, crystallinity, band gap and crystalline size. [ABSTRACT FROM AUTHOR]

• Ultralight PAFP/GONRs-A aerogel was prepared facilely by solvothermal polymerization method. • The aerogel showed a low density, large specific surface area and high phosphorus content. • The aerogel presented an unexpectedly high adsorption capacity and selectivity for thorium. • Phosphonic groups play an important role in Th(IV) adsorption. • DFT calculations revealed the coordination modes of Th(IV) with the aerogel, confirming the experimental results. An ultralight three-dimensional porous network phosphonic acid functionalized polymer/graphene oxide nanoribbons aerogel (PAFP/GONRs-A) was prepared using trimethylolpropane trimethacrylate (TRIM) and vinylphosphonic acid (VPA) as monomers via solvothermal polymerization method for thorium capture from aqueous solutions. The synthesized aerogel presented a low density (10.6 mg cm−3), large specific surface area (433.2 m2 g−1) and high phosphorus content (18.2%). The adsorption process of Th(IV) on PAFP/GONRs-A was pH-dependent, spontaneous and endothermic, and well described by the pseudo-second-order kinetic and Langmuir isotherm model. Under optimal experimental conditions (10 mg of adsorbent dosage, 50 mL of solution volume, 240 min of contact time, 298 K of temperature), PAFP/GONRs-A presented an excellent high adsorption capacity of thorium, with maximum capacity of 457.9 mg g−1 at a pH of 3.0, and maximum thorium-selectivity of 87.1% at a pH of 2.0. The values of ΔG for Th(IV) adsorption on PAFP/GONRs-A were calculated to be −21.78, –23.32, −24.87 and −26.41 kJ mol−1 at 283, 298, 313 and 328 K, respectively. Density functional theory (DFT) calculations and X-ray photoelectron spectroscopy (XPS) revealed that Th(IV) ions were fixed in aerogel by coordinating with the P = O groups of PAFP/GONRs-A, and both 1:2 ratio of Th(IV) with the P = O ligands on the same graft chain and 1:4 ratio of Th(IV) with P = O ligands on two distinct graft chains could jointly contribute to the adsorption of Th(IV) on PAFP/GONRs-A. This work offers a facile approach for synthesizing the phosphonic acid functionalized graphene oxide nanoribbons aerogel and demonstrates that PAFP/GONRs-A has high potential as a candidate adsorbent for the capture of thorium from aqueous solution. [ABSTRACT FROM AUTHOR]