Co2P2O7 Microplate/Bacterial Cellulose–Derived Carbon Nanofiber Composites with Enhanced Electrochemical Performance

Abstract

Nanocrystalline Co2P2O7 and carbon nanofiber (Co2P2O7/CNFs) composites with enhanced electrochemical performance were obtained by calcination after a hydrothermal process with NH4CoPO4∙H2O/bacterial cellulose precursors under an argon atmosphere. SEM images showed that the CNFs were highly dispersed on the surfaces of Co2P2O7 microplates. The diagonal size of the Co2P2O7 plates ranged from 5 to 25 µm with thicknesses on a nanometer scale. Notably, with the optimal calcining temperature, the Co2P2O7/CNFs@600 material has higher specific micropore and mesopore surface areas than other samples, and a maximal specific capacitance of 209.9 F g−1, at a current density of 0.5 A g−1. Interestingly, CNF composite electrodes can enhance electrochemical properties, and contribute to better electrical conductivity and electron transfer. EIS measurements showed that the charge–transfer resistance (Rct) of the CNF composite electrodes decreased with increasing calcination temperature. Furthermore, the Co2P2O7/CNF electrodes exhibited higher energy and power densities than Co2P2O7 electrodes.

Dinitrogen Reduction Coupled with Methanol Oxidation for Low Overpotential Electrochemical NH3 Synthesis Over Cobalt Pyrophosphate as Bifunctional Catalyst

“…In this scenario, the adsorption of methanol could be faster than CO over catalyst surface due to the presence of pyrophosphate groups which increase the polarity of the composite and in turn the activity of catalyst by facile adsorption of MeOH. [ 49 ] Our strategy to replace sluggish OER with MOR at anode during overall NH 3 synthesis is apparent from the less negative oxidation potentials during MOR than OER (around 0.2 V @ 10 mA cm −2 ) and the increased anodic current density in presence of MeOH by CoPPi, as shown in Figure 5a. This could be assigned to the nanosheets with flower‐like assembly of CoPPi, which provides wide‐open active sites with uniform channels for electrolyte transfer.…”

On Capacitance and Energy Storage of Supercapacitor with Dielectric Constant Discontinuity

“…Understanding the surface polarization effect can increase our ability to control the EDL structure and disclose work mechanisms for many practical applications, such as the design of a supercapacitor (SC) [ 25 , 26 , 27 , 28 ], modulating three-dimensional conformation of polyelectrolyte brush [ 29 ], self-assembly [ 30 , 31 ], ionic profiles [ 22 , 23 , 32 ], and surface force [ 21 , 33 , 34 , 35 , 36 , 37 , 38 , 39 ].…”

Fe metal‐organic framework/pyrolyzed bacterial cellulose composite as a high‐performance anode for lithium‐ion batteries

“…The structure of BC comprises a unique three‐dimensional network of cellulose nanofibers with plenty of nanopores and a vast surface area 20 . Moreover, pyrolysis of BC converted cellulose nanofibers into carbon nanofibers 21,22 . The pyrolyzed BC (pBC) shows excellent electrical conductivity due to the graphitization of cellulose at high temperatures.…”

“…20 Moreover, pyrolysis of BC converted cellulose nanofibers into carbon nanofibers. 21,22 The pyrolyzed BC (pBC) shows excellent electrical conductivity due to the graphitization of cellulose at high temperatures. Thus, its electrical conductivity depends on pyrolysis temperature and approaches ~0.2 S cm À1 after pyrolysis at 1000 C. 23 The pBC has been explored for potential utilization in many energy devices, such as supercapacitors, 24 fuel cells, 25 and batteries, 26 due to its high porosity, excellent electrical performance, and chemical stability.…”