Phase Evolution and Electrochemical Properties of Nanometric Samarium Oxide for Stable Protonic Ceramic Fuel Cells.

Electrochemical properties of metal oxide have a strong correlation with the crystalline structures. In this work, the effect of calcination temperature on the phase evolution and electrochemical properties of Sm O was systematically evaluated. The results demonstrate that the sample calcinated at 700 °C (SM-700) is composed of a pure cubic phase while it begins to convert into a monoclinic phase at a temperature above 800 °C and fully converts into a monoclinic phase at 1100 °C.

Unveiling the role of lithium in cerium oxide based ceramic fuel cells employing lithium compounds as the anode.

Cerium oxide based ceramic fuel cells (CFCs) enable a good cell performance with high ionic conductivity when a lithium compound is utilized as the anode material. However, the mechanism of enhancement of the ionic conductivity and its effect on the fuel cell performance as well as the stability involved the lithium effect have not been fully understood in this stage. In this paper, the role of lithium was unveiled through experimental measurements and DFT calculations in cerium oxide-based CFCs.

Nickel-iron nanoparticles encapsulated in carbon nanotubes prepared from waste plastics for low-temperature solid oxide fuel cells.

Low-temperature solid oxide fuel cells (LT-SOFCs) are a promising next-generation fuel cell due to their low cost and rapid start-up, posing a significant challenge to electrode materials with high electrocatalytic activity. Herein, we reported the bimetallic nanoparticles encapsulated in carbon nanotubes (NiFe@CNTs) prepared by carefully controlling catalytic pyrolysis of waste plastics. Results showed that plenty of multi-walled CNTs with outer diameters (14.

Development of a Core-Shell Heterojunction TiO /SrTiO Electrolyte with Improved Ionic Conductivity.

The front cover artwork is provided by Prof. Faze Wang's group at the Southeast University. The built-in electric field created by the semiconductor heterostructure confines the proton transport on the surface layer of the nanocomposite core-shell heterostructure imparting faster ion transport and lower activation energy.

Development of a Core-Shell Heterojunction TiO /SrTiO Electrolyte with Improved Ionic Conductivity.

Lately, semiconductor-membrane fuel cells (SMFCs) have attained significant interest and great attention due to the deliverance of high performance at low operational temperatures, <550 °C. This work has synthesized the nanocomposite core-shell heterostructure (TiO -SrTiO ) electrolyte powder by employing the simple hydrothermal method for the SMFC. The SrTiO was grown in situ on the surface of TiO to form a core-shell structure.

Surface-Engineered Homostructure for Enhancing Proton Transport.

Ultra-wide bandgap semiconductor samarium oxide attracts great interest because of its high stability and electronic properties. However, the ionic transport properties of Sm O have rarely been studied. In this work, Ni doping is proposed to be used for electronic structure engineering of Sm O .

Tunable magneto-optical and interfacial defects of Nd and Cr-doped bismuth ferrite nanoparticles for microwave absorber applications.

Tunable microwave absorption characteristics are highly desirable for industrial applications such as antenna, absorber, and biomedical diagnostics. Here, we report BiNdCrFeO (x = 0, 0.05, 0.

A self-healing catalyst for electrocatalytic and photoelectrochemical oxygen evolution in highly alkaline conditions.

While self-healing is considered a promising strategy to achieve long-term stability for oxygen evolution reaction (OER) catalysts, this strategy remains a challenge for OER catalysts working in highly alkaline conditions. The self-healing of the OER-active nickel iron layered double hydroxides (NiFe-LDH) has not been successful due to irreversible leaching of Fe catalytic centers. Here, we investigate the introduction of cobalt (Co) into the NiFe-LDH as a promoter for in situ Fe redeposition.

Superionic Conductivity in Ceria-Based Heterostructure Composites for Low-Temperature Solid Oxide Fuel Cells.

Ceria-based heterostructure composite (CHC) has become a new stream to develop advanced low-temperature (300-600 °C) solid oxide fuel cells (LTSOFCs) with excellent power outputs at 1000 mW cm level. The state-of-the-art ceria-carbonate or ceria-semiconductor heterostructure composites have made the CHC systems significantly contribute to both fundamental and applied science researches of LTSOFCs; however, a deep scientific understanding to achieve excellent fuel cell performance and high superionic conduction is still missing, which may hinder its wide application and commercialization. This review aims to establish a new fundamental strategy for superionic conduction of the CHC materials and relevant LTSOFCs.

Junction and energy band on novel semiconductor-based fuel cells.

Fuel cells are highly efficient and green power sources. The typical membrane electrode assembly is necessary for common electrochemical devices. Recent research and development in solid oxide fuel cells have opened up many new opportunities based on the semiconductor or its heterostructure materials.

High Photovoltage Inverted Planar Heterojunction Perovskite Solar Cells with All-Inorganic Selective Contact Layers.

Inverted planar heterojunction perovskite solar cells based on all-inorganic selective contact layers show great promise for commercialization owing to their competitiveness in terms of cost and stability. However, the power conversion efficiencies (PCEs) of the few reported perovskite solar cells with this type of device structure have been limited by relatively low photovoltages. Here, we propose a new device structure comprising electron beam-evaporated nickel and niobium oxides as the hole and electron selective contact layers, respectively.

Few-Layer MoS Nanosheets Encapsulated in N-Doped Carbon Hollow Spheres as Long-Life Anode Materials for Lithium-Ion Batteries.

Two-dimensional molybdenum disulfide (MoS ) has been recognized as a promising anode material for lithium-ion batteries (LIBs) due to its high theoretical capacity, but its rapid capacity decay owing to poor conductivity, structure pulverization, and polysulfide dissolution presents significant challenges in practical applications. Herein, triple-layered hollow spheres in which MoS nanosheets are fully encapsulated between inner carbon and outer nitrogen-doped carbon (NC) were fabricated. Such an architecture provides high conductivity and efficient lithium-ion transfer.

The rational design of hierarchical MoS nanosheet hollow spheres sandwiched between carbon and TiO@graphite as an improved anode for lithium-ion batteries.

Molybdenum disulfide (MoS) shows high capacity but suffers from poor rate capability and rapid capacity decay, which greatly limit its practical applications in lithium-ion batteries. Herein, we successfully prepared MoS nanosheet hollow spheres encapsulated into carbon and titanium dioxide@graphite, denoted as TiO@G@MoS@C, hydrothermal and polymerization approaches. In this hierarchical architecture, the MoS hollow sphere was sandwiched by graphite and an amorphous carbon shell; thus, TiO@G@MoS@C exhibited effectively enhanced electrical conductivity and withstood the volume changes; moreover, the aggregation and diffusion of the MoS nanosheets were restricted; this advanced TiO@G@MoS@C fully combined the advantages of a three-dimensional architecture, hollow structure, carbon coating, and a mechanically robust TiO@graphite support, achieving improved specific capacity and long-term cycling stability.

Engineering graphene and TMDs based van der Waals heterostructures for photovoltaic and photoelectrochemical solar energy conversion.

Graphene and two-dimensional (2D) transition metal dichalcogenides (TMDs) have attracted significant interest due to their unique properties that cannot be obtained in their bulk counterparts. These atomically thin 2D materials have demonstrated strong light-matter interactions, tunable optical bandgap structures and unique structural and electrical properties, rendering possible the high conversion efficiency of solar energy with a minimal amount of active absorber material. The isolated 2D monolayer can be stacked into arbitrary van der Waals (vdWs) heterostructures without the need to consider lattice matching.

A one-step method to fabricate novel three-dimensional GaP nanopore arrays for enhanced photoelectrochemical hydrogen production.

Gallium phosphide nanopore arrays with unique three-dimensional interior architectures (3D GaP NPs) are fabricated by electrochemical etching in a neutral solution. As the photoanodes for photoelectrochemical (PEC) hydrogen production, the 3D GaP NPs exhibited a larger photocurrent density (5.65 mA cm at 0 V vs.

Nickel skeleton three-dimensional nitrogen doped graphene nanosheets/nanoscrolls as promising supercapacitor electrodes.

A novel nickel skeleton 3D nitrogen doped graphene (N-GR/NF) superstructure with interconnected graphene nanosheets and nanoscrolls was synthesized using a facile two-step method. By varying the precursor concentration, the assembly of a graphene aerogel can be easily regulated, yielding different micro-structures and morphologies which accelerate the fast electron/ion transportation. The N-GR/NF composites demonstrate enhanced capacitance of 250 F g at 5 A g, good rate performance (237 F g at the current density of 12 A g) and cycle stability (90.

Galvanic displacement assembly of ultrathin CoO nanosheet arrays on nickel foam for a high-performance supercapacitor.

High-performance supercapacitors are very desirable for many portable electronic devices, electric vehicles and high-power electronic devices. Herein, a facile and binder-free synthesis method, galvanic displacement of the precursor followed by heat treatment, is used to fabricate ultrathin CoO nanosheet arrays on nickel foam substrate. When used as a supercapacitor electrode the prepared CoO on nickel foam exhibits a maximum specific capacitance of 1095 F g at a current density of 1 A g and good cycling stability of 71% retention after 2000 cycling tests.

Fast Growth of Highly Ordered TiO Nanotube Arrays on Si Substrate under High-Field Anodization.

Abstract: Highly ordered TiO nanotube arrays (NTAs) on Si substrate possess broad applications due to its high surface-to-volume ratio and novel functionalities, however, there are still some challenges on facile synthesis. Here, we report a simple and cost-effective high-field (90-180 V) anodization method to grow highly ordered TiO NTAs on Si substrate, and investigate the effect of anodization time, voltage, and fluoride content on the formation of TiO NTAs. The current density-time curves, recorded during anodization processes, can be used to determine the optimum anodization time.

Synchronous exfoliation and assembly of graphene on 3D Ni(OH) for supercapacitors.

Nowadays, new approaches to fabricate high-performance electrode materials are of vital importance in the renewable energy field. Here, we present a facile synthesis procedure of 3D Ni(OH)/graphene hybrids for supercapacitors via synchronous electrochemical-assisted exfoliation and assembly of graphene on 3D Ni(OH) networks. With the assistance of an electric field, the electrochemically exfoliated high-quality graphene can be readily, uniformly assembled on the surfaces of 3D Ni(OH).

Unique Three-Dimensional InP Nanopore Arrays for Improved Photoelectrochemical Hydrogen Production.

Ordered three-dimensional (3D) nanostructure arrays hold promise for high-performance energy harvesting and storage devices. Here, we report the fabrication of InP nanopore arrays (NPs) in unique 3D architectures with excellent light trapping characteristic and large surface areas for use as highly active photoelectrodes in photoelectrochemical (PEC) hydrogen evolution devices. The ordered 3D NPs were scalably synthesized by a facile two-step etching process of (1) anodic etching of InP in neutral 3 M NaCl electrolytes to realize nanoporous structures and (2) wet chemical etching in HCl/H3PO4 (volume ratio of 1:3) solutions for removing the remaining top irregular layer.

Engineering MoSx/Ti/InP Hybrid Photocathode for Improved Solar Hydrogen Production.

Due to its direct band gap of ~1.35 eV, appropriate energy band-edge positions, and low surface-recombination velocity, p-type InP has attracted considerable attention as a promising photocathode material for solar hydrogen generation. However, challenges remain with p-type InP for achieving high and stable photoelectrochemical (PEC) performances.

InP nanopore arrays for photoelectrochemical hydrogen generation.

We report a facile and large-scale fabrication of highly ordered one-dimensional (1D) indium phosphide (InP) nanopore arrays (NPs) and their application as photoelectrodes for photoelectrochemical (PEC) hydrogen production. These InP NPs exhibit superior PEC performance due to their excellent light-trapping characteristics, high-quality 1D conducting channels and large surface areas. The photocurrent density of optimized InP NPs is 8.

Erratum to: A Facile Self-assembly Synthesis of Hexagonal ZnO Nanosheet Films and Their Photoelectrochemical Properties.

[This corrects the article DOI: 10.1007/s40820-015-0068-y.].

A Facile Self-assembly Synthesis of Hexagonal ZnO Nanosheet Films and Their Photoelectrochemical Properties.

Here, large-scale and uniform hexagonal zinc oxide (ZnO) nanosheet films were deposited onto indium tin oxide (ITO)-coated transparent conducting glass substrates via a facile galvanic displacement deposition process. Compared with other commonly used solution methods, this process avoids high temperature and electric power as well as supporting agents to make it simple and cost-effective. The as-fabricated ZnO nanosheet films have uniform hexagonal wurtzite structure.