Tengfei Qiu

Rod-coating: towards large-area fabrication of uniform reduced graphene oxide films for flexible touch screens.

A novel strategy is developed for the large-scale fabrication of reduced graphene oxide films directly on flexible substrates in a controlled manner by the combination of a rod-coating technique and room-temperature reduction of graphene oxide. The as-prepared films display excellent uniformity, good transparency and conductivity, and great flexibility in a touch screen.

High Volumetric Capacity Silicon-Based Lithium Battery Anodes by Nanoscale System Engineering

The nanostructuring of silicon (Si) has recently received great attention, as it holds potential to deal with the dramatic volume change of Si and thus improve lithium storage performance. Unfortunately, such transformative materials design principle has generally been plagued by the relatively low tap density of Si and hence mediocre volumetric capacity (and also volumetric energy density) of the battery. Here, we propose and demonstrate an electrode consisting of a textured silicon@graphitic carbon nanowire array. Such a unique electrode structure is designed based on a nanoscale system engineering strategy. The resultant electrode prototype exhibits unprecedented lithium storage performance, especially in terms of volumetric capacity, without the expense of compromising other components of the battery. The fabrication method is simple and scalable, providing new avenues for the rational engineering of Si-based electrodes simultaneously at the individual materials unit scale and the materials ensemble scale.

Au@MnO2 core-shell nanomesh electrodes for transparent flexible supercapacitors

A novel Au@MnO2 supercapacitor is presented. The sophisticated core-shell architecture combining an Au nanomesh core with a MnO2 shell on a flexible polymeric substrate is demonstrated as an electrode for high performance transparent flexible supercapacitors (TFSCs). Due to their unique structure, high areal/gravimetric capacitance and rate capability for TFSCs are achieved.

High‐Efficiency and Room‐Temperature Reduction of Graphene Oxide: A Facile Green Approach Towards Flexible Graphene Films

A novel, green, and highly efficient strategy for room-temperature reduction of solid-state graphene oxide films has been successfully developed using hydrogen-involved reduction with the assistance of a small amount of Pd catalyst. Based on this approach, flexible reduced graphene oxide films with high conductivity can be achieved and a roll-to-roll technique is expected.

Reduced graphene oxide nanoribbon networks: a novel approach towards scalable fabrication of transparent conductive films.

An innovative approach is developed for the high-throughput, large-area, and low-cost fabrication of reduced graphene oxide (RGO) nanoribbon networks by using electrospun polymer-based nanowires as the etching mask. Combined with their tunable, controllable structures and transmittance/conductivity properties, the as-fabricated RGO nanoribbon networks exhibit potential as transparent conductive film electrodes, for example, in electrochromic devices.

Graphene-templated formation of 3D tin-based foams for lithium ion storage applications with a long lifespan

3D tin-based foams with tailorable pore structures are developed through a graphene-templated freeze-drying approach. Pore structure effects on the electrochemical properties of the G/SnO2@C composite foam are investigated. Further the carbon coating endows the foam-like nanocomposite with superior cycling stability and rate capability.

Synergistically engineered self-standing silicon/carbon composite arrays as high performance lithium battery anodes

The synergistically engineered self-standing silicon/carbon composite arrays exhibit unprecedented lithium storage performance, including a high specific capacity of 1510 mA h g−1 based on the total electrode weight, extraordinary cycling stability with nearly 100% capacity retention over 600 cycles, and areal capacity approaching the value of commercial lithium-ion batteries (3.9 mA h cm−2).

A fast room-temperature strategy for direct reduction of graphene oxide films towards flexible transparent conductive films

Chemically reduced graphene oxide (rGO) is widely studied as a transparent electrode, as it can be cheaply prepared on a large scale, easily integrated into flexible devices, and contributes to excellent device performances. However, the commonly used reduction methods for converting graphene oxide (GO) films into rGO ones generally involve toxic reagents or complex transfer steps. In this report, we develop a simple short-term room-temperature strategy for the direct fabrication of rGO-based transparent conductive films on flexible substrates, where tin (Sn) is used to promote the conversion of pre-deposited GO films into rGO ones. The thus-prepared rGO films exhibit sheet resistances of 6.7–17.3 kΩ sq−1 and transparencies of 75–81% at 550 nm, indicating great potential of the here-developed methodology for the fabrication of graphene-based transparent conductive films, under conditions without any heating and transferring processes, as well as toxic agents.

Metallic nanomesh with disordered dual-size apertures as wide-viewing-angle transparent conductive electrode

With the rapid development of display-related markets, transparent conductive films (TCFs) with wide viewing angles, high transmittance and low sheet resistance are in high demand. However, as a promising TCF material, metallic membranes with a submicrometer-sized periodicity pattern fabricated by currently available techniques always reveal the angle-dependent structure color which can be a major issue in the development of wide-angle viewing display-related applications. In this work, we demonstrate an Au nanomesh with disordered dual-size apertures as a novel TCF with wide viewing angles which is made via a modified nanosphere lithography technique. The as-prepared Au nanomesh film shows good optoelectronic properties (Rs = 160 Ω sq(-1), T = 80%; Rs = 8 Ω sq(-1), T = 57%) that are similar to the Au nanomesh with single size apertures, while the former exhibits excellent wide-angle viewing performance. There is no obvious change in the film when the viewing angle, the light incidence angle or the orientation of substrate vary in the range of 0-90°. In contrast, a rainbow color is observed with the film with ordered single-size apertures. Electrochromic devices based on the novel metallic film show more uniform color distribution than the devices based on metallic film with ordered single-size apertures under indoor natural light irradiation. These findings demonstrate the applicability of the Au nanomesh film with dual-size apertures in enhancing display quality of high-performance optoelectronic devices.