Strong coupled spinel oxide with N-rGO for high-efficiency ORR/OER bifunctional electrocatalyst of Zn-air batteries

Chemically Binding Vanadium Sulfide in Carbon Carriers to Boost Reaction Kinetics for Potassium Storage

“…To further illustrate the presence of the V–C bond, we find that the V–C peak (1145 cm –1 ) also appears in Fourier transform infrared spectra of the CB-VS@NSCNFs (Figure S3). The main peaks in the high-resolution S 2p spectrum (Figure d) at 163.8/164.9 and 161.5/163.1 eV come from C–S and V–S, respectively, while the peak centered at 168.1 eV corresponds to the oxidized sulfur species (SO x ). − The C 1s spectrum discloses the existence of C–S and C–N bonds (285.6 eV), indicating the successful doping of heteroatom N and S in CNFs. − Moreover, the deconvolution peak located at 283.3 eV can be considered as the V–C bond, again demonstrating the strong anchoring contact between the V 5.45 S 8 nanoparticles and the CNFs (Figure e). , Additionally, the deconvolution results of the N 1s peak (Figure f) indicate the presence of pyridinic-N (398.4 eV), pyrrolic-N (400.7 eV), and graphitic-N (401.6 eV), further verifying the doping of the N element into the CNFs. ,, Meanwhile, the XPS results (C 1s, V 2p, S 2p spectra) of the control sample (B-VS/C) are revealed in Figure S1b–d, whose chemical states of the respective elements are quite different from those of CB-VS@NSCNFs. For B-VS/C, first, there is no C–N bond in the deconvolution peak of C 1s; second, there is no V–C bond in the V 2p spectrum, indicating that B-VS/C is not strongly anchored to the carbon matrix.…”

“…45,46 Additionally, the deconvolution results of the N 1s peak (Figure 2f) indicate the presence of pyridinic-N (398.4 eV), pyrrolic-N (400.7 eV), and graphitic-N (401.6 eV), further verifying the doping of the N element into the CNFs. 26,47,48 Meanwhile, the XPS results (C 1s, V 2p, S 2p spectra) of the control sample (B-VS/C) are revealed in Figure S1b−d, whose chemical states of the respective elements are quite different from those of CB-VS@NSCNFs. For B-VS/C, first, there is no C−N bond in the deconvolution peak of C 1s; second, there is no V−C bond in the V 2p spectrum, indicating that B-VS/C is not strongly anchored to the carbon matrix.…”

Transition metal oxides with perovskite and spinel structures for electrochemical energy production applications

“…Carbon materials are excellent candidates to fulfil this role taking into account their interesting properties such as high electrical conductivity, high thermal stability, high surface area, and, in some cases, low price. Different types of carbon materials have been used for this purpose, such as carbon blacks (De Koninck et al, 2007;Kéranguéven et al, 2015), carbon nanotubes (Alexander et al, 2018;Zhang et al, 2020e;Li et al, 2019), graphene-based materials (Hu et al, 2015;Samanta and Raj, 2019;Rebekah et al, 2020;Zhuang et al, 2021), activated carbons (Hu et al, 2018;Flores-Lasluisa et al, 2019b) and nitrogen-doped carbon materials (Chen et al, 2017;Park et al, 2015;Najam et al, 2020;Wu et al, 2018b;Mathumba et al, 2020;Liu et al, 2021). Nevertheless, no sufficient attention is paid to the effect of the structure (at different levels) and surface chemistry of the carbon material on the interaction with the metal oxide and on its role on the catalytic activity improvement.…”

Positive regulation of active sites for oxygen evolution reactions by encapsulating NiFe2O4 nanoparticles in N-doped carbon nanotubes in situ to construct efficient bifunctional oxygen catalysts for rechargeable Zn–air batteries

“…[27][28][29] However, there is not a consistent understanding about the origin of the OER activity of the catalysts. Metals or alloys in the TM-N-C catalysts were considered to afford the OER active sites according to some research studies, 30,31 and the OER activities of metal carbides, 32,33 metal nitrides 34,35 and metal oxides [36][37][38][39] were also revealed in other investigations.…”