A novel S-scheme heterojunction of Cd0.5Zn0.5S/BiOCl with oxygen defects for antibiotic norfloxacin photodegradation: Performance, mechanism, and intermediates toxicity evaluation.

S-Scheme MIL-101(Fe) octahedrons modified Bi2WO6 microspheres for photocatalytic decontamination of Cr(VI) and tetracycline hydrochloride: Synergistic insights, reaction pathways, and toxicity analysis

Clean and sustainable energy is one of the greatest challenges of this century. Of the several renewable energy sources that can address this challenge, nothing has greater potential than solar energy. However, to harness the solar power and to ensure its world-wide uptake, efficient, cheap, environmentally benign, and durable solar cells are essential. The unprecedented enhancement in the power conversion efficiency of hybrid perovskite solar cells from 3.9% in 2009 to over 20% today shows their great promise to meet the above challenges, provided issues with their stability and environmental impact can be addressed. Despite considerable research in the past five years, answers to some fundamental questions as well as an atomic level understanding of these materials remain a challenge. Using multi-scale approach and a comprehensive study of over 40 materials, we have identified the key parameters and mechanisms that control the basic properties and the stability of hybrid perovskites. We show that these materials can be viewed as super alkali halide crystals where alkali and halogen ions are respectively replaced by super-alkali and super-halogen species. This opens the path to a new series of hybrid perovskites based on super-ions as building blocks with improved stability and functionality.

http://absimage.aps.org/image/MAR16/MWS_MAR16-2015-001878.pdf

Super-ion inspired colorful hybrid perovskite solar cells.

The implication of photocatalytic reactions based on semiconductor heterojunction are critical for impacting both environment and energy. Scientists are passionate for developing their photocatalytic competence. The high recombination rates of photoinduced charge carriers beside their limited oxidation and reduction abilities for solely semiconductor lead to the construction of heterojunctions by several approaches. Ranging from type-I, type-II, Schottky, and Z-scheme heterojunctions, the Step-Scheme (S-Scheme) heterojunction composed of two independent semiconductors with different band energies was emerged. A brief discussion on the difference between previously studied heterojunction types compared to the newly proposed S-Scheme is presented in this review in terms of charge-transfer mechanism and key characterization tools are presented. The current design strategies and perspective applications of S-scheme heterojunction photocatalysts in fuel production, carbon cycling (namely oxidation of organic compounds and reduction of carbon dioxide), as well as other important redox reactions are selectively highlighted as emerging green approach for clean energy and environmental remediation. Moreover, another related environmental reactions such as oxidation of nitrous oxide to green products and reduction of heavy metal ions to less toxic chemicals are discussed including our current research. The current challenges and perspectives for S-Scheme photocatalysis are also summarized. 

S-scheme heterojunctions: emerging designed photocatalysts toward green energy and environmental remediation redox reactions

Because of their high energy density, low cost, and environmental friendliness, lithium-sulfur (Li-S) batteries are one of the potential candidates for the next-generation energy-storage devices. However, they have been troubled by sluggish reaction kinetics for the insoluble Li2S product and capacity degradation because of the severe shuttle effect of polysulfides. These problems have been overcome by introducing transition metal compounds (TMCs) as catalysts into the interlayer of modified separator or sulfur host. This review first introduces the mechanism of sulfur redox reactions. The methods for studying TMC catalysts in Li-S batteries are provided. Then, the recent advances of TMCs (such as metal oxides, metal sulfides, metal selenides, metal nitrides, metal phosphides, metal carbides, metal borides, and heterostructures) as catalysts and some helpful design and modulation strategies in Li-S batteries are highlighted and summarized. At last, future opportunities toward TMC catalysts in Li-S batteries are presented.

Understanding the Catalytic Kinetics of Polysulfide Redox Reactions on Transition Metal Compounds in Li-S Batteries.

http://manuscript.elsevier.com/S1005030222000512/pdf/S1005030222000512.pdf

Oxygen vacancies induced narrow band gap of BiOCl for efficient visible-light catalytic performance from double radicals

The practical progress of lithium-sulfur batteries is hindered by the serious shuttle effect and the slow oxidation-reduction kinetics of polysulfides. Herein, the ZnFe2O4-Ni5P4 Mott-Schottky heterojunction material is prepared to address these issues. Benefitting from a self-generated built-in electric field, ZnFe2O4-Ni5P4 as an efficient bidirectional catalysis regulates the charge distribution at the interface and accelerates electron transfer. Meanwhile, the synergy of the strong adsorption capacity derived from metal oxides and the outstanding catalytic performance that comes from metal phosphides strengthens the adsorption of polysulfides, reduces the energy barrier during the reaction, accelerates the conversion between sulfur species, and further accelerates the reaction kinetics. Hence, the cell with ZnFe2O4-Ni5P4/S harvests a high discharge capacity of 1132.4 mAh g-1 at 0.5C and displays a high Coulombic efficiency of 99.3% after 700 cycles. The ZnFe2O4-Ni5P4/S battery still maintains a capacity of 610.1 mAh g-1 with 84.4% capacity retention after 150 cycles at 0.1C under a high sulfur loading of 3.2 mg cm-2. This work provides a favorable reference and advanced guidance for developing Mott-Schottky heterojunctions in lithium-sulfur batteries.

ZnFe2O4-Ni5P4 Mott-Schottky Heterojunctions to Promote Kinetics for Advanced Li-S Batteries.

Bismuth oxyhalides (BiOX) nano-materials are considered to be the most encouraging candidates to deal with environmental remediation, energy conversion, and degradation of organic pollutants because of their attractive characteristics, such as appropriate band structure, suppressed charges recombination ability, and good catalytic activity. The pure BiOX does not justify the advisable fine-tune photocatalytic efficiency. Therefore, several BiOX morphologies are synthesized, such as atomic layers, ultrathin nano-sheets, nano-spheres, and nano-tubes to enhance multiple applications performance. Moreover, the photocatalytic sites, quantum efficiency, charge separation, and light absorption efficiency of BiOX are largely studied for higher photocatalytic activity. Generally, we reviewed the highly advanced strategies for enhanced photocatalytic activities including simultaneous decontamination of wastewater as well as energy conversion. Furthermore, the review objective; is to summarize recent scientific and technological challenging about bismuth oxyhalides composites including fabrication methods, photocatalytic activity, and performance improving challenging of BiOX based photocatalysts. Moreover, we proposed comprehensive upcoming positive advances and developments comprising potential applications on behalf of BiOX based photocatalysts. 

Recent advances in BiOX-based photocatalysts to enhanced efficiency for energy and environment applications

The weak van der Waals interactions of the one-dimensional (1D) chainlike VS4 crystal structure can enable fast charge-transfer kinetics in metal ion batteries, but its potential has been rarely exploited in depth. Herein, a thermodynamics-driven morphology manipulation strategy is reported to tailor VS4 nanosheets into 3D hierarchical self-assembled architectures including nanospheres, hollow nanospheres, and nanoflowers. The ultrathin VS4 nanosheets are generated via 2D anisotropic growth by the strong driving force of coordination interaction from ammonium ions under microwave irradiation and then evolve into 3D sheet-assembled configurations by adjusting the thermodynamic factors of temperature and reaction time. The as-synthesized VS4 nanomaterials present good electrochemical performances as the anode materials for sodium-ion batteries. In particular, the hollow VS4 nanospheres show a specific capacity of 1226.7 mAh g-1 at 200 mA g-1 current density after 100 cycles. The hierarchical nanostructures with large specific surface area and structural stability can overcome the difficulty of sodium ions embedding into the bulk material interior and provide more reactive materials at the same material mass loading compared with other morphologies. Both experiment and DFT calculations suggest that VS4 nanosheets reduce reaction kinetic impediment of sodium ion in battery operating. This work demonstrates a way of the morphological design of 2D VS4 nanosheets and application in sodium ion storage.

Jia-Huan Hou

Papers

Oxygen vacancies induced narrow band gap of BiOCl for efficient visible-light catalytic performance from double radicals

ZnFe2O4-Ni5P4 Mott-Schottky Heterojunctions to Promote Kinetics for Advanced Li-S Batteries.

Recent advances in BiOX-based photocatalysts to enhanced efficiency for energy and environment applications

Ammonium-Modified Synthesis of Vanadium Sulfide Nanosheet Assemblies toward High Sodium Storage.

Defect Engineering in Polymeric Carbon Nitride with Accordion Structure for Efficient Photocatalytic CO2 Reduction and H2 Production