Jianjun Ding

Highly efficient photocatalytic hydrogen evolution of graphene/YInO3 nanocomposites under visible light irradiation

Visible-light-driven hydrogen evolution with high efficiency is important in the current photocatalysis research. Here we report for the first time the design and synthesis of a new graphene-semiconductor nanocomposite consisting of YInO3 nanoparticles and two-dimensional graphene sheets as efficient photocatalysts for hydrogen evolution under visible light irradiation. The graphene/YInO3 nanocomposites were synthesized using a facile solvothermal method in which the formation of graphene and the deposition of YInO3 nanoparticles on the graphene sheets can be achieved simultaneously. The addition of graphene as a cocatalyst can narrow the band gap of YInO3 to visible photon energy and prolong the separation and lifetime of electron-hole pairs by the chemical bonding between YInO3 and graphene. The photocatalytic reaction with this nanocomposite reaches a high H2 evolution rate of 400.4 μmol h(-1) g(-1) when the content of graphene is 0.5 wt%, over 127 and 3.7 times higher than that of pure YInO3 and Pt/YInO3, respectively. This work can provide an effective approach to the fabrication of graphene-based photocatalysts with high performance in the field of energy conversion.

Hydrothermal Synthesis of CaIn2S4-Reduced Graphene Oxide Nanocomposites with Increased Photocatalytic Performance

A series of CaIn2S4-reduced graphene oxide (RGO) nanocomposites with different RGO contents were fabricated using a facile hydrothermal approach. During the hydrothermal process, the reduction of graphene oxide to RGO, in situ deposition of synthesized CaIn2S4 nanoparticles on RGO nanosheets and formation of chemical-bonding CaIn2S4-RGO nanocomposites were performed simultaneously. Under visible light irradiation, the as-prepared CaIn2S4-RGO nanocomposites showed enhanced photocatalytic performance for rhodamine B degradation and phenol oxidation. The sample with 5 wt % RGO hybridized CaIn2S4 exhibited the highest photocatalytic activity. The enhancement of photocatalytic performance may be related to the increased adsorption/reaction sites, positive shift of the valence band potential, and high separation efficiency of photogenerated charge carriers due to the electronic interaction between CaIn2S4 and RGO. We hope that this work can not only provide an in-depth study on the photocatalytic mechanism of RGO-enhanced activity, but also provide some insights for fabricating efficient and stable RGO-based photocatalysts in the potential applications of purifying polluted water resources.

Mechanism Study of Photocatalytic Degradation of Gaseous Toluene on TiO2 with Weak-Bond Adsorption Analysis Using In Situ Far Infrared Spectroscopy

The development of far infrared spectroscopy offers a powerful method for comprehensive study in adsorption structure and photocatalytic degradation mechanism of photocatalysis. This study presented an improved in situ diffuse reflectance infrared Fourier transform spectroscopy technique in far infrared region for investigation of weak-bond adsorption and photocatalytic degradation of gaseous toluene on the surface of TiO2. It was found that toluene tends to be adsorbed on the hydroxyl group via three possible sites, the ortho-, meta-, and para-adsorption site, instead of ipso-structure. The methyl group of toluene is consumed first during the process of toluene photocatalytic degradation. Based on these, a reaction route for the photocatalytic degradation of gaseous toluene on TiO2 surface was proposed.Graphical Abstract

Application of Parallel Synthesis and High Throughput Characterization in Photocatalyst Discovery

The last decade has seen significant progresses in the application of combinatorial approaches and high-throughput screening in photocatalyst discovery. This paper aims at providing a comprehensive review on the parallel synthesis and high-throughput characterization of photocatalysts, including the development of instrumentation, strategy of experiment, preparation of libraries, high-throughput screening technique and data analysis. The review ends with a summary of the remaining challenges and prospects on combinatorial photocatalyst discovery.

Rapid Discovery of a Photocatalyst for Air Purification by High-Throughput Screening

Despite several decades of intensive studies, only a few commercial photocatalysts have been discovered by means of the conventional one‐at‐a‐time synthesis and characterization. Herein, a high‐throughput screening of photocatalysts for air purification using an infrared microscope, equipped with a set of homemade in situ gas reaction cells and a gas dosing system, is described. 1.0 % La3+/0.4 % Nd3+‐TiO2 was rapidly selected as an active photocatalyst for toluene degradation with a mineralization rate of 93.4 % at a humidity level of 70 % in 2 h. The excellent agreement between our combinatorial results and those of the bulk samples confirms the reliability of the developed rapid screening method. In addition, the investigation of the effects of pretreatment with NH3 and H2S on the photocatalytic activity also offers some information about the surface modification for air purification.

The study of luminescence of rare-earth organic complexes sensitized Eu 3+ complex in PMMA matrix using combinatorial method

A combinatorial approach has been utilized for researching the luminescence of rare-earth ions complexes (RE(DBM)3⋅Phen, RE=Dy, La, Gd, Sm, Y) sensitized Eu complex in PMMA matrix. The results show that the La complex has the maximum sensitization efficiency among these sensitization ions. The luminescent intensities increase as the Eu content increase in PMMA matrix. The La complex exhibits higher sensitization efficiency at lower Eu content in PMMA matrix. At a content of 5% Eu complex, the maximum sensitization efficiency of La is more than 20 times. Introduction Luminescent rare-earth organic complexes, such as Eu and Tb complexes chelating with β-diketone’s ligands, are of both fundamental and technological interest, due to their characteristic luminescence properties, such as extremely sharp emission bands, long lifetime and potential high internal quantum efficiency. Regarded as light-conversion materials, these complexes have been widely applied in a variety of areas, such as fluoroimmunoassays [1,2], electroluminescence devices [3,4], and polymer optical fiber [5,6], etc. The luminescence of rare-earth ions stems from intra-4f transitions, which in principal are forbidden transitions, results in relatively low emission intensity. From a practical point of view, it is necessary to further enhance the emission intensity. An effective approach is to change the complexes with different kinds of ligands that have broad and intense absorption bands [7,8], which transfers a part of its energy to the higher energy levels of rare-earth ions. Another way is to mix the complexes with different sensitization ions [9,10]. In both cases, there exist energy transfer processes. In this paper, combinatorial method was used to investigate the effects of different kinds and JJ9.7.1 Mat. Res. Soc. Symp. Proc. Vol. 804