Enhanced field emission from titanium dioxide nanotube arrays decorated with graphene sheets and silver nanoparticles

• GSs/Ag/TiO2 NTAs hybrid emitter was fabricated using electrochemical deposition process.
• The GSs/Ag/TiO2 NTAs exhibits good field emission performance with the low turn-on and threshold field, and good stability.
• GSs and Ag nanoparticles deposition on TiO2 NTAs increase the field enhancement factor and improve the contact resistance, respectively.

The TiO2 nanotube arrays decorated with graphene sheets (GSs) and Ag nanoparticles were prepared on Ti foils and field emission performances were explored in detail. The conventional electrochemical anodization process was used to synthesize TiO2 nanotube arrays on Ti foils. The GSs and Ag nanoparticles were deposited on as-prepared TiO2 nanotube arrays by electrophoretic deposition process and chemical deposition. The field emission properties of samples were dramatically improved after depositing GSs and Ag nanoparticles on TiO2 nanotube arrays. Compared with pristine TiO2 nanotube arrays, the TiO2 nanotube arrays decorated with GSs and Ag nanoparticles composite film show good field emission stability and a higher field enhancement factor of 3450. The turn-on and threshold fields can be decreased from 6.63 to 2.68 V/μm and from 15.28 to 6.13 V/μm, respectively. Quantitative discussion about the hybrid hetero-nanostructure field emission improvement is presented. The good field emission properties of the decorated TiO2 make it a promising candidate for applying in high-performance emission device.