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Synthesis of well dispersed, Large area and monolayer of rGO by Wet chemical route for sensing applications

(Performed by Aamir Rasheed)

http://www.aerogelgraphene.com/graphene-sensors/
https://www.sciencedirect.com/science/article/pii/S0956566316300860?via%3Dihub

Project description

(Courtesy of Mr. Aamir Rasheed at NDnMP)
✔ To detect low traces of dangerous gases such as ammonia and nitrogen dioxide sensibly and cheaply
✔ Preparation of high quality RGO film for sensing applications
✔ Improvement of RGO conductivity for electrical devices
✔ A monolayer and well connected film of RGO for good sensing device
✔ Large size RGO film for proper coverage of sensing area in device


◎ Hummers Method
(http://aappsbulletin.org/myboard/read.php?Board=featurearticles&id=159)
• A Solution processable route to synthesize a large area RGO film
• A cost effective and easy protocol to get RGO in a universal solvent (water)
• A well-dispersed RGO solution to get a large area film on any substrate

Why? The reasons of the research

◎ Among different forms of graphene used as gas-sensing materials, reduced graphene oxide is one of the most convenient and economical materials to integrate with Si-based electronics, which is very important to graphene-based gas sensors.
(DOI: 10.1039/C2JM30378G)
✔ Use of Graphene as a sensing material in sensors

✔ Control of electrical conductivity and RGO size for sensing applications

✔ A scalable solution processable technique to achieve fine RGO film on any substrate

✔ Connection between electrodes of sensing device using well dispersed RGO

Why is the project important?

(https://www.nature.com/articles/srep04684.pdf)
✔ To detect low traces of dangerous gases such as ammonia and nitrogen dioxide sensibly and cheaply

✔ Synthesis of a large area monolayer graphene for sensing applications

✔ An easy and cost effective method for large production

✔ A solution of poor dispersion of RGO for sensors

✔ An easy transfer method to get a well connected monolayer RGO film on sensing area of device





Synthesis of Highly Conductive Two-Dimensional Ti2CTx Film

(Performed by Wen He5)

(http://www.dom.ua/content/view/789/585/
Chem. Soc. Rev., 2018, 47, 5109-5124)

Main findings


(http://www.mdpi.cohttp://ceramics.org/ceramic-tech-today/two-dimensional-mxene-carbides-pack-four-times-more-lithiumm/2076-3417/7/1/19)
◎ Synthesized Recipe
1. 1 g of Ti3AlC2 powders were slowly added in 10 mL of HF solution.
2. The solution mixture was stirred at 1000 rpm for 48 h at 25°C.
3. After the etching reaction, the mixture were centrifuged and cleaned with deionized (DI) water at 3500 rpm for 5min each, until the pH reached to 6
4. The dark green supernatant was discarded
5. . After filtration process to remove excess water, the settled powders were dried in air for 24 h

Key results

✔ SEM & XRD patterns
(Courtesy of Mr. Wen He at NDnMP)
✔ I-V measurements
(Courtesy of Mr. Wen He at NDnMP)

Why? The reasons of the research


(https://experti.tech/mxene-veshja-qe-ushqen-baterine/)
✔ MXenes are a novel family of 2D early transition metal carbides, nitrides, and carbonitrides
✔ The oxygen and/or fluoride groups present at the surface of the Mn+1XnTx layers weakly bond the individual layers together, resulting in MXenes being susceptible to exfoliation to produce colloidal solutions of single MXene flakes
✔ The rich transition metal chemistry of MXenes enables tuning their electronic properties from metallic to semiconducting
✔ Mxenes also possess other merits which are listed as the followings:
   • Hydrophilic surfaces
   • Good flexibility
   • Easy processing
   • High metallic conductivities

Why is the project important?

(ACS Nano 11, 11, 11135-11144)
✔ Two-dimensional (2D) materials and their characteristics have attracted extensive attention in the field of materials science. However, there remains a big challenge to develop new materials for large-scale 2D films with improved transmittance and conductivity that can be fabricated at low cost

✔ MXenes can host many different cations between their layers. It could be used for a wide range of applications including electronic devices, sensors, reinforcement for composites, and energy storage and harvesting materials





Synthesis of High Quality 3D Graphene by Chemical Vapor Deposition

(Performed by Yongteng Qian)

(Courtesy of Mr. Yongteng Qian at NDnMP)

Project description


(Courtesy of Mr. Yongteng Qian at NDnMP)
◎ Synthesis
✔ Preparation of high quality 3D graphene for energy storage applications
✔ Graphene with the 3D structure can enhance the surface area
✔ Graphene with the 3D structure can supply more surface active sites
✔ Graphene with the 3D structure can provide more transfer pathway for active materials

Main findings


(Courtesy of Mr. Yongteng Qian at NDnMP)
✔ Monolayer graphene has many advantages, including high conductivity, high thermal conductivity, high carrier mobility, etc
✔ The Raman spectra demonstrate the peak of 2D/G ratio more than 2, indicating our 3D graphene is monolayer
✔ Importantly, no defect peak appear at Raman spectra exhibit the 3D graphene is high quality
✔ SEM results demonstrate the 3D graphene has highly interconnected 3D porous network and large surface area, which can not only supply more growth sites for others materials, but also can provide more surface active sites

Why? The reasons of the research


(Courtesy of Mr. Yongteng Qian at NDnMP)
✔ Synthesis of high quality graphene with 3D structure by CVD is limited

✔ Synthesis of high quality graphene with 3D structure by CVD is limited

✔ An easy and cost effective method for large production

✔ Ni foam as a 3D structure template

Applications

(Courtesy of Mr. Yongteng Qian at NDnMP)
✔ Growth of ZnO nanoflakes on 3D graphene for nanogenerator

• Successful synthesis of poly(dimethylsiloxane) / ZnO nanoflakes / 3D graphene (PDMS/ZnO NFs/3D Gr) heterostructures using Ni foams as the template substrate via a facile route for a high-performance energyharvester application. The PDMS/ZnO NFs/3D Gr heterostructure-based hybrid energy harvester simultaneously exploits the piezoelectric effect and triboelectrification and shows peak-to-peak output voltages up to 122 V and peak-to-peak current densities up to 51 μA cm−2, resulting in an ultrahigh power density of 6.22 mW cm−2. Furthermore, This superior output power density is capable of instantaneously powering 68 LEDs, activated simply by palm-tapping.