2.3. Evaluation of Photocatalytic Water Splitting 6507 2.3.1. Photocatalytic Activity 6507 2.3.2. Photocatalytic Stability 6507 3. UV-Active Photocatalysts for Water Splitting 6507 3.1. d0 Metal Oxide Photocatalyts 6507 3.1.1. Ti-, Zr-Based Oxides 6507 3.1.2. Nb-, Ta-Based Oxides 6514 3.1.3. W-, Mo-Based Oxides 6517 3.1.4. Other d0 Metal Oxides 6518 3.2. d10 Metal Oxide Photocatalyts 6518 3.3. f0 Metal Oxide Photocatalysts 6518 3.4. Nonoxide Photocatalysts 6518 4. Approaches to Modifying the Electronic Band Structure for Visible-Light Harvesting 6519

Semiconductor-based Photocatalytic Hydrogen Generation

Jenny Schneider,*,† Masaya Matsuoka,‡ Masato Takeuchi,‡ Jinlong Zhang, Yu Horiuchi,‡ Masakazu Anpo,‡ and Detlef W. Bahnemann*,† †Institut fur Technische Chemie, Leibniz Universitaẗ Hannover, Callinstrasse 3, D-30167 Hannover, Germany ‡Faculty of Engineering, Osaka Prefecture University, 1 Gakuen-cho, Sakai Osaka 599-8531, Japan Key Lab for Advanced Materials and Institute of Fine Chemicals, East China University of Science and Technology, Shanghai 200237, China

Understanding TiO2 photocatalysis: mechanisms and materials.

In this chapter, we will restrict our attention to the ferrites and a few other closely related materials. The great interest in ferrites stems from their unique combination of a spontaneous magnetization and a high electrical resistivity. The observed magnetization results from the difference in the magnetizations of two non-equivalent sub-lattices of the magnetic ions in the crystal structure. Materials of this type should strictly be designated as “ferrimagnetic” and in some respects are more closely related to anti-ferromagnetic substances than they are to ferromagnetics in which the magnetization results from the parallel alignment of all the magnetic moments present. We shall not adhere to this special nomenclature except to emphasize effects, which are due to the existence of the sub-lattices.

Ferromagnetic materials

UV-Visible ار راد ن .د TiO2 ( تیفرظ راون مان هب نورتکلا یاراد یژرنا زارت لماش VB و ) رگید زارت ی یژرنا اب ( ییاناسر راون مان هب نورتکلا زا یلاخ و رتلااب VB یم ) .دشاب ت ود نیا نیب یژرنا توافت یژرنا فاکش زار ، پگ دناب هدیمان یم .دوش هک ینامز زا نورتکلا لاقتنا VB هب VB یم ماجنا دریگ ، TiO2 اب ودح یژرنا بذج د ev 2 / 3 ، نورتکلا تفج کی دیلوت یم هرفح .دیامن و نورتکلا هرفح ی نا اب هدش دیلوت یم کرتشم حطس هب لاقت ثعاب دناوت شنکاو ماجنا اه یی ددرگ . TiO2 دربراک ،دراد یدایز یاه هلمج زا یم ناوت اوه یگدولآ هیفصت یارب (CO2) و بآ و ... نآ زا هدافتسا درک .

Advanced Nanoarchitectures for Solar Photocatalytic Applications

Generations Yi Ma,† Xiuli Wang,† Yushuai Jia,† Xiaobo Chen,‡ Hongxian Han,*,† and Can Li*,† †State Key Laboratory of Catalysis, Dalian Institute of Chemical Physics, Chinese Academy of Sciences and Dalian National Laboratory for Clean Energy, 457 Zhongshan Road, Dalian 116023, China ‡Department of Chemistry, College of Arts and Sciences, University of Missouri-Kansas City, 5100 Rockhill Road, Kansas City, Missouri 64110, United States

Titanium dioxide-based nanomaterials for photocatalytic fuel generations.

The control of size, shape, and physical properties by surface modifications are of immense interest in materials which are of technological importance. The ZnO-based wide bandgap semiconductor nanoparticles have gained significant interest in the research community due to its large exciton binding energy (60 meV). Further substantial renewed interest in ZnO-based compounds is due to the possible realization of p-type conduction and ferromagnetic behavior when doped with transition metals. In this report we present interesting results on the ZnO nanoparticle system in which the control of dopants, morphology, and the surface modification can influence significantly the physical properties of the ZnO nanoparticles. First, we present the methods to control the morphology of the ZnO particle to obtain nanorods. As an example we show the effect of Li dopant on the morphology control of Co and Ni doped ZnO. The effect of morphology on the magnetic properties of these compounds is discussed further. We also demonstrate the effect of the n-type charge carriers on the magnetic and optical properties by doping aliovalent cations in Zn(Co)O. Following this we comment on the magnetic property manipulations by surfactant treatment of transition metal (TM) doped ZnO and defect stabilization in ZnO by Mg doping. The magnetic coupling is RKKY-like both with and without Li co-doping. Finally, we provide the significant implications of these results on the nanorods structures of room temperature ferromagnetic materials by first-principles modeling. These theoretical analyses demonstrate that Li co-doping has primarily two effects in bulk Zn1−x M x O (with M = Co or Ni). First, the Li-on-Zn acceptors increase the local magnetic moment by depopulating the M 3d minority spin-states. Second, Li-on-Zn prefer to be closer to the M atoms to compensate the M–O bonds and to locally depopulate the 3d states, and this will help in forming high aspect nanostructures. The observed room temperature ferromagnetism in Li co-doped Zn1−x M x O nanorods can therefore be explained by the better rod morphology in combination with locally ionizing the magnetic M atoms.

Experimental and Theoretical Investigations of Dopant, Defect, and Morphology Control on the Magnetic and Optical Properties of Transition Metal Doped ZnO Nanoparticles

Charge Pumping by Contact Electrification Using Electrostatic Force Microscopy in Bi- and Trilayered MoS2 Nanosheets

Optical trapping allows the trapping and manipulation of dielectric microparticles. However, full control over all six degrees of freedom of the trapped object is challenging. Here, we use ferromagnetic iron-doped upconversion microparticles for simultaneous optical trapping and magnetic micromanipulation that allows full control over all translational and rotational degrees of freedom. These microparticles have a low absorption that allows optical trapping and a high coercivity and saturation magnetization that allow magnetic manipulation. The particles will enable micromanipulation experiments, for example, in single-molecule biophysics. 

Simultaneous Optical Trapping and Electromagnetic Micromanipulation of Ferromagnetically Doped NaYF4 Microparticles

A new platform for research and development of inexpensive and efficient solar cells has evolved based on hybrid perovskite absorber material. The power conversion efficiency of polycrystalline perovskite solar cells shot from 3.8% in 2009 to 25.7% in 2022. Even though perovskite solar cells are close to commercialization, their poor operational stability in real time is a matter of concern. The major roadblock is moisture-induced material degradation at polycrystalline absorber material grain boundaries. Single crystalline perovskite materials are explored to overcome this problem. The superior stability of single-crystalline perovskite over polycrystalline counterpart is the significantly reduced grain boundary regions. Other advantages, including high absorption coefficient, low trap densities, long diffusion lengths, large carrier lifetimes, and increased mobility, have made these single-crystalline perovskites more relevant for solar cell application. This review emphasizes the importance of single-crystalline perovskite over polycrystalline perovskite. Further, it provides a comprehensive account of various methods for the growth of single-crystalline perovskite material, their structural, optical, and electrical properties, emphasizing device applications. The methods employed for developing single crystals by different routes have been elaborately discussed. The challenges encountered in integrating the single-crystal monoliths for device applications, the methods evolved to develop single-crystalline films, performance and stability of single-crystalline devices are presented. The future scope of research including uniform thickness controllable films with proper interface engineering, inorganic perovskites for solar cell applications, and potential optoelectronic applications of single-crystal perovskites are discussed. 

Chandran Sudakar

Papers

Experimental and Theoretical Investigations of Dopant, Defect, and Morphology Control on the Magnetic and Optical Properties of Transition Metal Doped ZnO Nanoparticles

Charge Pumping by Contact Electrification Using Electrostatic Force Microscopy in Bi- and Trilayered MoS2 Nanosheets

Simultaneous Optical Trapping and Electromagnetic Micromanipulation of Ferromagnetically Doped NaYF4 Microparticles

Single-Crystal Hybrid Lead Halide Perovskites: Growth, Properties, and Device Integration for Solar Cell Application

Statistical Optimization of Citric acid production fromalkali-treated Coffee husk with lemon Peel Pomace by usingAspergillus niger