Three-Dimensional Monolayer Graphene and TiO2 Hybrid Architectures for High-Efficiency Electrochemical Photovoltaic Cells

AbstractAchieving high-efficiency photoelectrochemical water splitting requires a better understanding of ion kinetics, e.g., diffusion, adsorption and reactions, near the photoelectrode’s surface. However, with macroscopic three-dimensional electrodes, it is often difficult to disentangle the contributions of surface effects to the total photocurrent from that of various factors in the bulk. Here, we report a photoanode made from a InSe crystal monolayer that is encapsulated with monolayer graphene to ensure high stability. We choose InSe among other photoresponsive two-dimensional (2D) materials because of its unique properties of high mobility and strongly suppressing electron–hole pair recombination. Using the atomically thin electrodes, we obtained a photocurrent with a density >10 mA cm−2 at 1.23 V versus reversible hydrogen electrode, which is several orders of magnitude greater than other 2D photoelectrodes. In addition to the outstanding characteristics of InSe, we attribute the enhanced photocurrent to the strong coupling between the hydroxide ions and photo-generated holes near the anode surface. As a result, a persistent current even after illumination ceased was also observed due to the presence of ions trapped holes with suppressed electron-hole recombination. Our results provide atomically thin materials as a platform for investigating ion kinetics at the electrode surface and shed light on developing next-generation photoelectrodes with high efficiency.

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Finite Element Modeling for Steel Cord Analysis in Radial Tires

Tire Science and Technology ◽

10.2346/tire.13.410104 ◽

2013 ◽

Vol 41 (1) ◽

pp. 60-79 ◽

Cited By ~ 1

Author(s):

Wei Yintao ◽

Luo Yiwen ◽

Miao Yiming ◽

Chai Delong ◽

Feng Xijin

Keyword(s):

Finite Element ◽

High Efficiency ◽

Force Measurement ◽

Three Dimensional ◽

Local Stress ◽

Tension Force ◽

Center Line ◽

Element Analysis ◽

Design Variables ◽

Steel Cord

ABSTRACT: This article focuses on steel cord deformation and force investigation within heavy-duty radial tires. Typical bending deformation and tension force distributions of steel reinforcement within a truck bus radial (TBR) tire have been obtained, and they provide useful input for the local scale modeling of the steel cord. The three-dimensional carpet plots of the cord force distribution within a TBR tire are presented. The carcass-bending curvature is derived from the deformation of the carcass center line. A high-efficiency modeling approach for layered multistrand cord structures has been developed that uses cord design variables such as lay angle, lay length, and radius of the strand center line as input. Several types of steel cord have been modeled using the developed method as an example. The pure tension for two cords and the combined tension bending under various loading conditions relevant to tire deformation have been simulated by a finite element analysis (FEA). Good agreement has been found between experimental and FEA-determined tension force-displacement curves, and the characteristic structural and plastic deformation phases have been revealed by the FE simulation. Furthermore, some interesting local stress and deformation patterns under combined tension and bending are found that have not been previously reported. In addition, an experimental cord force measurement approach is included in this article.

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Construction of the Cellulose Nanofibers (CNFs) Aerogel Loading TiO2 NPs and Its Application in Disposal of Organic Pollutants

Polymers ◽

10.3390/polym13111841 ◽

2021 ◽

Vol 13 (11) ◽

pp. 1841

Author(s):

Kang Li ◽

Xuejie Zhang ◽

Yan Qin ◽

Ying Li

Keyword(s):

High Efficiency ◽

Sol Gel ◽

Cellulose Nanofibers ◽

Three Dimensional ◽

Good Mechanical Property ◽

Polar Groups ◽

Dimensional Network ◽

Natural Polysaccharide ◽

Valuable Method ◽

Adsorption Capability

Aerogels have been widely used in the adsorption of pollutants because of their large specific surface area. As an environmentally friendly natural polysaccharide, cellulose is a good candidate for the preparation of aerogels due to its wide sources and abundant polar groups. In this paper, an approach to construct cellulose nanofibers aerogels with both the good mechanical property and the high pollutants adsorption capability through chemical crosslinking was explored. On this basis, TiO2 nanoparticles were loaded on the aerogel through the sol-gel method followed by the hydrothermal method, thereby the enriched pollutants in the aerogel could be degraded synchronously. The chemical cross-linker not only helps build the three-dimensional network structure of aerogels, but also provides loading sites for TiO2. The degradation efficiency of pollutants by the TiO2@CNF Aerogel can reach more than 90% after 4 h, and the efficiency is still more than 70% after five cycles. The prepared TiO2@CNF Aerogels have high potential in the field of environmental management, because of the high efficiency of treating organic pollutes and the sustainability of the materials. The work also provides a choice for the functional utilization of cellulose, offering a valuable method to utilize the large amount of cellulose in nature.

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Near-field thermophotovoltaics for efficient heat to electricity conversion at high power density

Nature Communications ◽

10.1038/s41467-021-24587-7 ◽

2021 ◽

Vol 12 (1) ◽

Author(s):

Rohith Mittapally ◽

Byungjun Lee ◽

Linxiao Zhu ◽

Amin Reihani ◽

Ju Won Lim ◽

...

Keyword(s):

Power Density ◽

High Power ◽

High Efficiency ◽

Near Field ◽

Electrical Power ◽

Photovoltaic Cells ◽

High Power Density ◽

Pv Cell ◽

Electrical Power Output ◽

Power Densities

AbstractThermophotovoltaic approaches that take advantage of near-field evanescent modes are being actively explored due to their potential for high-power density and high-efficiency energy conversion. However, progress towards functional near-field thermophotovoltaic devices has been limited by challenges in creating thermally robust planar emitters and photovoltaic cells designed for near-field thermal radiation. Here, we demonstrate record power densities of ~5 kW/m2 at an efficiency of 6.8%, where the efficiency of the system is defined as the ratio of the electrical power output of the PV cell to the radiative heat transfer from the emitter to the PV cell. This was accomplished by developing novel emitter devices that can sustain temperatures as high as 1270 K and positioning them into the near-field (<100 nm) of custom-fabricated InGaAs-based thin film photovoltaic cells. In addition to demonstrating efficient heat-to-electricity conversion at high power density, we report the performance of thermophotovoltaic devices across a range of emitter temperatures (~800 K–1270 K) and gap sizes (70 nm–7 µm). The methods and insights achieved in this work represent a critical step towards understanding the fundamental principles of harvesting thermal energy in the near-field.

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Three-dimensional macroporous wood-based selective separation membranes decorated with well-designed Nd(III)-imprinted domains: A high-efficiency recovery system for rare earth element

Journal of Colloid and Interface Science ◽

10.1016/j.jcis.2020.11.030 ◽

2020 ◽

Author(s):

Yilin Wu ◽

Rongxin Lin ◽

Faguang Ma ◽

Wendong Xing ◽

Jianming Pan

Keyword(s):

Rare Earth ◽

Rare Earth Element ◽

Earth Element ◽

High Efficiency ◽

Three Dimensional ◽

Selective Separation ◽

Separation Membranes ◽

Recovery System

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Advances in coupled axial turbine and nonaxisymmetric exhaust volute aerodynamics for turbomachinery

Proceedings of the Institution of Mechanical Engineers Part G Journal of Aerospace Engineering ◽

10.1177/0954410020966454 ◽

2020 ◽

pp. 095441002096645

Author(s):

Jie Gao ◽

Chunde Tao ◽

Dongchen Huo ◽

Guojie Wang

Keyword(s):

Performance Improvement ◽

High Efficiency ◽

Three Dimensional ◽

Great Influence ◽

Aerodynamic Characteristics ◽

Turbine Engines ◽

Gas Turbine Engines ◽

Axial Turbine ◽

Flow Interactions ◽

And Performance

Marine, industrial, turboprop and turboshaft gas turbine engines use nonaxisymmetric exhaust volutes for flow diffusion and pressure recovery. These processes result in a three-dimensional complex turbulent flow in the exhaust volute. The flows in the axial turbine and nonaxisymmetric exhaust volute are closely coupled and inherently unsteady, and they have a great influence on the turbine and exhaust aerodynamic characteristics. Therefore, it is very necessary to carry out research on coupled axial turbine and nonaxisymmetric exhaust volute aerodynamics, so as to provide reference for the high-efficiency turbine-volute designs. This paper summarizes and analyzes the recent advances in the field of coupled axial turbine and nonaxisymmetric exhaust volute aerodynamics for turbomachinery. This review covers the following topics that are important for turbine and volute coupled designs: (1) flow and loss characteristics of nonaxisymmetric exhaust volutes, (2) flow interactions between axial turbine and nonaxisymmetric exhaust volute, (3) improvement of turbine and volute performance within spatial limitations and (4) research methods of coupled turbine and exhaust volute aerodynamics. The emphasis is placed on the turbine-volute interactions and performance improvement. We also present our own insights regarding the current research trends and the prospects for future developments.

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