Search

Tunable Electromagnetic Interference (EMI) shielding behaviors of 2D MXene (Nb 2 CT x) were explored via different exfoliation conditions. Stacked, lamellar few-layer, oxygen-related surface functional groups, and structural defects along with oxidative products of Nb 2 CT x were identified by tuning chemical etching conditions during one-step exfoliation process. Exfoliation of Nb 2 CT x with a tightly packed stacked structure remarked at lower etching times. The unpacking of Nb 2 CT x into lamellar morphology followed by separated few-layer Nb 2 CT x remarked at moderate etching time, whereas structural misalignment, defects, and oxidation of Nb 2 CT x occurred during prolonged chemical etching times. Synergistic effect of one-step extracted few-layers and lamellar structured Nb 2 CT x favorably enrich the assembly of multiple electrical conductive pathways responsible for absorption dominated EMI shielding performance in X- and Ku-band region. The assembled wax nanocomposites with 80% of Nb 2 CT x loading exfoliated at 100 h etching time at a thickness of 1 mm exhibited EMI shielding effectiveness of about 44.09 ± 1.99 dB at 12 GHz, and its EMI attenuation mechanism explained by conduction and eddy current loss. The combined action of few-layer and lamellar Nb 2 CT x nanostructures could be interesting for making novel shielding materials; open a new avenue for niobium series in the MXene family for elaborated applications. • Investigation on one step exfoliation of few-layer transition metal carbide (Nb2CTx) MXene by tuning exfoliation conditions. • The Nb 2 CT x wax nanocomposites exhibited EMI shielding effectiveness of about 44.09±1.99 dB at 12 GHz. • Synergistic action of few-layer and laminar Nb 2 CT x favorable conducting network lead higher absorbing capacity of EM waves. [ABSTRACT FROM AUTHOR]

• Graphitic carbon-supported TiO 2 hybrid nanostructure was established from Ti 3 C 2 T x. • The nanostructure showed higher photocatalytic degradation of dye than TiO 2 NPs. • The bactericidal performance of the hybrid was remarkable under irradiation. The present study addresses the establishment of a highly reactive catalyst derived from Ti 3 C 2 T x (MXene), which is a graphitic carbon-supported TiO 2 hybrid nanostructure for photocatalytic and bacteriostatic applications. The graphitic carbon-supported TiO 2 nanoparticles, which were placed onto a Ti 3 C 2 T x backbone as ternary hybrids under the controlled oxidation of isopropylamine delaminated Ti 3 C 2 T x , were demonstrated to be semiconducting nanostructures. Beneficially, the oxygen-related vacancies in TiO 2 along with graphitic carbon support in the metallic Ti 3 C 2 T x heterostructures exhibited distinct methylene blue dye degradation under UV irradiation at a rate constant of (k) of 0.035 ± 0.003 min−1. The demonstrated superior catalytic performance of the assembled hybrid structure was attributed to the formation of multiple interfacial junctions formed by graphitic carbon, TiO 2 nanoparticles, and Ti 3 C 2 T x , which created distinct intermediate energy levels for electron-hole pair separation and improved the catalytic performance. The synthesized hybrid nanostructures also exhibited excellent antibacterial activity; approximately 97.4% of E. coli was killed by the nanostructures under light exposure due to the excessive radicals that caused oxidative stress on bacterial cells. The developed hybrid nanostructures from the controlled oxidation of delaminated Ti 3 C 2 T x are expected to be superior materials for photocatalytic and bacteriostatic applications. [ABSTRACT FROM AUTHOR]

• Self-reduction and oxidative synthesis of MXene/Metal Oxides-Ag are demonstrated. • Nb 2 CT x /Nb 2 O 5 -Ag hybrid assembly attains reflection dominated shielding performance. • The ternary nanostructure shows maximum EMI SE about 72.04 dB K u band regions. The development of smart, structured hybrid materials with superior electrical conductivity are vastly desired for the depletion of unwanted electromagnetic interference (EMI). Herein, novel multilayered two-dimensional MXene/Metal Oxides-Ag ternary hybrid nanostructures with various heterogeneous assemblies were constructed by self-reduction and oxidation of MXene (Nb 2 CT x and Ti 3 C 2 T x) in the presence of metallic salt (AgNO 3), and its EMI shielding performance in X- and K u -band are demonstrated. The effect of different silver nitrate addition into MXene on their structural evaluation reveals that the successful formation of MXene/Metal Oxides-Ag (Nb 2 CT x /Nb 2 O 5 -Ag; Ti 3 C 2 T x /TiO 2 -Ag) ternary hybrid nanostructures derived from MXene (Nb 2 CT x ; Ti 3 C 2 T x). Remarkably, the Nb 2 CT x /Nb 2 O 5 -Ag hybrid assembly attains reflection dominated shielding performance with a maximum total shielding effectiveness of 68.76 dB and 72.04 dB in the X- and K u -band region respectively at a thickness of 1 mm compared to other nanostructures. The large enhancement in electromagnetic shielding capability of ternary nanostructure attributed to the strong electrical conductivity and increased interface polarization and multiple reflection loss between the ternary interfaces. The synergistic effect of metallic silver nanoparticles, semiconducting metal oxides and conducting stacked multilayer causes to conduction loss, polarization effect (dipole, and interfacial polarization), and multiple reflections of incoming radiation favor the complete dissipation of EM waves. Consequently, the demonstrated simple, cost-effective, and large scale production of highly conductive composites could pave for the potential prospect materials in advanced EM wave shielding applications. [ABSTRACT FROM AUTHOR]

Construction of heterojunction and nitrogen doping is an effective approach for synthesizing photocatalysts with high quantum yield and efficient electron-hole separation. 2D MXene Ti 3 C 2 has been considered a good carbonaceous nanomaterial for designing heterojunction, while the original surface groups and stacked structure limit the electron-hole separation. Herein, a hybrid of nitrogen-doped Ti 3 C 2 nanosheets and TiO 2 nanoparticles (NPs) composed of TiO 2 NPs in situ growing on isopropyl amine (iPA) modified Ti 3 C 2 (iN-Ti 3 C 2) was developed for the first time. The novel iN-Ti 3 C 2 /TiO 2 hybrid exhibited an excellent ultraviolet-light photodegradation of methylene blue (MB), with a degradation rate (0.02642 min−1) significantly higher than that of pure TiO 2 NPs, bulk-Ti 3 C 2 /TiO 2 , dimethyl sulfoxide modified Ti 3 C 2 /TiO 2 hybrid, and hydrazine monohydrate modified Ti 3 C 2 /TiO 2 hybrid. The formation of heterojunction between iN-Ti 3 C 2 and TiO 2 and its role in the photocatalysis were systematically analyzed using various characterization techniques and density functional theory calculation. The iPA modification exfoliated Ti 3 C 2 and doped N on Ti 3 C 2 nanosheets; the in situ grown TiO 2 NPs formed efficient heterojunctions with the nanosheets; the N-doping facilitated electron migration in Ti 3 C 2 and inhibited the recombination of photogenerated electron-hole pairs; •OH dominated the photodegradation of MB. This work provides a new approach of constructing efficient photocatalysts for the treatment of organics-polluted water. ga1 • TiO 2 NPs in situ grew on N-doped Ti 3 C 2 with isopropyl amine. • N-doping enhanced the electrochemical property of Ti 3 C 2. • The iN-Ti 3 C 2 /TiO 2 heterojunction inhibited the electron-hole recombination. • The iN-Ti 3 C 2 /TiO 2 hybrid nanomaterial exhibited superb photodegradation of MB. [ABSTRACT FROM AUTHOR]

MXene based composites are promising candidates with a broad range of potential applications, especially in electrochemical energy storage and conversion devices. In this work, we demonstrate the preparation of a novel MXene/N–CuMe 2 Pc (non-peripheral octamethyl-substituted copper (II) phthalocyanine) based composite as the electrode material in supercapacitors. The integration of highly redox-active N–CuMe 2 Pc into MXene leads to the large surface area, which enhances the active sites for electrochemical redox reactions. For instance, composite prepared with a weight ratio of 1:0.2 of MXene:N–CuMe 2 Pc (M10P2) exhibits remarkable maximum specific capacitance of 786.1 F g−1. The enhanced capacitance performance is attributed to the synergistic effect of water intercalated MXene layers and N–CuMe 2 Pc. The constructed M10P2 based symmetric supercapacitor shows excellent performance with a maximum energy density of 8.84 Wh kg−1 with a power density of 112.3 W kg−1. Additionally, the symmetric device exhibits outstanding cyclic stability (92.3%) even after 20,000 cycles with satisfactory Coulombic efficiency. This work proves the new insight of preparation of MXene/N–CuMe 2 Pc composites for high-performance next-generation supercapacitor sectors in the near future. Image 1 • MXene/N–CuMe 2 Pc composites have been synthesized with different ratios of N–CuMe 2 Pc. • The specific capacitance of the M10P2 composite is up to 786.1 F g−1. • N–CuMe 2 Pc enhances the active sites of MXene for electrochemical redox reactions. • The symmetric supercapacitor shows a high energy density of 8.84 Wh kg−1. • Symmetric supercapacitor exhibits 92.3% of capacitance retention after 20000 cycles. [ABSTRACT FROM AUTHOR]