Heteroatom Modified TiO₂/Graphene Aerogel Composites by Electron Beam Irradiation in Supercapacitors

Abstract

Heteroatom doping is an effective way to generate oxygen vacancies and improve the electrochemical properties of materials. However, the heteroatom doping process is more complicated and it is difficult to ensure the simultaneous generation of defects. In this work, TiO2 quantum dots/graphene aerogel composites were synthesized via a simple hydrothermal method. The N and S atoms were successfully incorporated by electron beam irradiation, and a large number of defects were introduced. The effects of irradiation dose on the doping amount, elemental morphology, and electrochemical properties of the compounds were further studied. The synergistic effect between graphene’s double-layer capacitance and TiO2 quantum dots’ pseudocapacitance, as well as the introduction of heteroatomic doping and defects, is beneficial to improve the electrochemical performance of the material. When used as an electrode material for supercapacitors, NT-NSG-140 at an irradiation dose of 140 kGy shows the best electrochemical performance. At a high current density of 5 A g–1, the NT-NSG-140 maintains a capacity of 127.8 F g–1. This work provides an environmentally friendly, simple, and efficient method for designing high-performance materials containing heteroatoms.

Porous Electrospun Carbon Nanofibers Bearing TiO2 Hollow Nanospheres for Supercapacitor Electrodes

“…Among various TMOs (MnO 2 , 13 NiO, 14 MoO 3 15 ), TiO 2 emerges as an attractive material for this purpose due to its cost-effectiveness, abundance, efficient charge transport pathways, high chemical stability, nontoxic nature, and environmental friendliness. 16 In this paper, we report a facile process for fabricating the porous carbon nanofibers bearing as-prepared TiO 2 hollow nanospheres (hTiO 2 ) electrodes using electrospinning followed by heat treatment for the first time. This process can increase the porosity and surface area of CNFs through the uniform distribution of hTiO 2 , which ultimately improves the specific capacitance of supercapacitor electrodes.…”

“…Additionally, conducting a systematic study on how as-prepared TMOs specifically affect the specific surface area and porosity of CNFs, thereby facilitating the electrochemical processes and ultimately enhancing the capacity for EDLC charge storage mechanism, is crucial. Among various TMOs (MnO 2 , NiO, MoO 3 ), TiO 2 emerges as an attractive material for this purpose due to its cost-effectiveness, abundance, efficient charge transport pathways, high chemical stability, nontoxic nature, and environmental friendliness …”

Investigating the Impact of Ag Nanoparticles on N and S Co‐Doped TiO2 for Battery‐Type Supercapacitor Application

“…For instance, Fu et al created a system using N and S TiO 2 combined with graphene, achieving a specific capacitance of 127.8 F g À 1 at 5 A g À 1 . [34] Weiqing et al developed a hydrogel electrode composed of N and S co-doped graphene with a maximum specific capacitance of 320 F g À 1 at 1 A g À 1 . [37] Liu et al achieved a specific capacitance of 223.7 F g À 1 at a scan rate of 2 mV s À 1 by developing Ni-TiO 2 co-doped with N and C. [38] On the other hand, Ojha et al demonstrated a specific capacitance of 328.88 F g À 1 at 1 A g À 1 for an electrode made of Mn-doped TiO 2 .…”

“…Moreover, this process leads to the creation of structural defects within the lattice, further enhancing its characteristics. [31,34] Such type of TiO 2 composites have improved electrical conductivities and advantageous in number of applications such as energy storage. Notably, N (3.04) and S (2.58) have higher electronegativity compared to Ti (1.54), making them an appealing co-doping heteroatom.…”