Energy: Directed reduction of graphene oxide for spontaneous electricity production

There are many forms of energy in nature, and the spontaneous diffusion of moisture can be a new type of green energy, which is widely found in nature. With the progress of scientific research, human beings have found that the symmetrical structure plays a vital role in the cell membrane of organisms, which can spontaneously produce built-in potential differences to maintain the osmotic pressure balance on both sides of the membrane. This interesting phenomenon promotes the study of bionic/artificial non-symmetrical structures and is widely used in the fields of ion selective transport, nar fluid sensing and permeable pressure production and electricity
in
. This kind of built-in potential induced by special non-symmetric structure can generate electric energy spontaneously without the help of mechanical motion, light, heat and other external stimuli, which is a new type of power generation which is different from the voltage, friction, thermoelectric and fluid power generation. However, until now, due to the complex cellular environment and the lack of effective structural regulation of synthetic materials, how to convert this spontaneously generated potential based on an unsympathetic structure into real-world electrical energy remains a huge challenge.
Figure 1. Symmetrical graphene oxide produces electrical schematics in the air

D. Cheng Huhu, Tsinghua University, and Professor
Quliang
team
constructed the symmetrical graphene oxide by means of directional thermal reduction, proposing a new type of generator
(Figure 1) that can spontaneously generate electricity from the air.
Figure 2. Self-generating performance map of an a symmetrical graphene oxide film
The researchers constructed a symmetrical porous graphene oxide (a-GOM) using a directional thermal reduction strategy, consisting of a partial thermal reduction (Pr-GO) and an unreverted graphene oxide. Among them, the oxygen-containing ernogeneum group in the Pr-GO layer shows a gradient distribution, the internal protons show the characteristics of concentration differences, while the unreverted GO layer has a uniform distribution of oxygen-containing ernogeneic group, which can provide abundant protons. Based on this particular non-symmetrical structure, a large number of protons in the GO layer will spontaneously spread to the lower side of the oxygen-containing ernogenic group under the concentration polarization of Pr-GO, significantly increasing the separation of charges within them. Without any stimulation, a 4 mm
2 size a-GOM can spontaneously generate voltages of up to 450 mV when placed in the atmosphere (Figure 2). And show good stability, in the atmospheric environment since the release of electricity 100 h, can still maintain 90% of the voltage value.
Figure 3. Integration and Application Demonstration of Electrical Appliances
Further, through a simple device stacking and assembly method, 60 production units can produce up to 11.2V voltage in series, successfully charging commercial capacitors and lighting lcd displays and LED digital tubes (Figure 3). In addition, by flexible packaging, the unit can be assembled into a flexible collapsible portable energy source, providing a broad range of applications in the field of flexible electronics and wearables.
This work, through the clever directional thermal reduction strategy, constructs the non-symmetrical graphene oxide self-generating material, realizes the high efficiency of self-generation under atmospheric conditions, and successfully applies the integration of flexible and portable power supply, which provides a new way of thinking for obtaining green, environmentally friendly and stable use of electricity from the environment.
results were recently published in
The first author of

Huang Yaxin
, a Ph.D. student, and Professor
Qu Liang body
and
Cheng Huhu
.
author of the paper is:
Huhu Cheng, Yaxin Huang, Fei Zhao, Ce Yang, Panpan Zhang, Lan Jiang Gaoquan Shi, Liangti Qu
Spontaneous power source source inmbient air of a well-directionally reduced graphene
Energy Environ. Sci.
,
2018
,
11
, 2839-2845, DOI: 10.1039/C8EE01502C
In recent years, Qu Liang's team has focused on advanced materials and new micronatural devices, as well as research and applications in energy, environment and other fields. Related work published in nature communications
(
Nature Communications
:
2018
,
9,4166
)
, Advanced Materials
(
Advanced Materials
:
2017
,
29
, 1604972;

, 2015
27
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Energy and Environmental Science (
Energy and Environmental Science
:
2018
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11
, 1730;

11,

2018;

, 2016
9
, 912), German Applied Chemistry
(
Angewandte Chemie International Edition
:
2018
, DOI:10.1002/anie.201810345;
2018
, DOI:10.1002/anie.201808835)
, Advanced Functional Materials
(
Advanced Functional Materials
:
2017
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2
7; 1703096;

, 2016
26
, 8784;
, nano-energy (
Nano Energy
:
2018
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46
, 297;
45

2018,
37;

2017
,
32, 329) and was invited to
(
Nature Reviews Materials
:
2017
,
2
, 17046)
, Chemical Research Review
(
Accounts of Chemical Research
:
2017
,
50
, 1663)
, Joule
(
Joule
:
2018
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2
, 245).