Hybrid oxidation methodologies (HOMs) and active site enrichment of 2D nanocatalyst through defects induction are ubiquitously used for generating adequate reactive oxygen species (ROS) in ...synergistic decontamination of nano hazards. In this study, 2D graphitic carbon nitride (2D-gCN), synthesized through a single-step liquid exfoliation methodology, depicts a tensile strain-induced planar defect intensified structure, as comprehended from microscopic, spectroscopic, diffraction, and photo-electrochemical (PEC) studies. Also, the piezo-photocatalytic capability of degrader 2D-gCN is revealed through a rapid removal of several noxious organic pollutants, i.e., methylene blue (MB, 97% in 16 min), bromophenol blue (BB, 88% in 16 min), and ampicillin (AMP, 75%, in 120 min) in a controlled catalytic condition. Rates for MB, BB, and AMP piezo-photo-dismissals are respectively ~ 16.4, 9.4, and 3.4 times higher than sole photocatalysis. The dismissal pathway consists of band bending through photon-aided piezo-cavitation, which leads to maximum ROS production and recombination suppression. Furthermore, LC–MS analysis confirms AMP remediation. In radicals trapping, OH, h
+
, and O
2
.−
are predominantly accountable for the AMP, BB, and MB dismissal, respectively. The piezo-photocatalytic stability has been assured through the morphological and bond characteristics of reusable 2D-gCN. So, using the HOM approach, 2D-gCN can be projected as a proficient remediator in wastewater treatments.
Graphical abstract
Display omitted
•Defects are strengthened through Gd ions chemisorption onto 2D-gCN electrode.•XPS, SBET, and HR-TEM findings assure the lattice defects of Gd3+/2D-gCN NSs.•Nyquist and Bode plots ...exhibit the capacitive nature of the electrodes.•Ion’s intercalation leads to enhance the areal capacitance via EDLC mechanism.•Complete retention of Csp (2.59 mF cm−2) over 1000th cycles for Gd3+/2D-gCN NSs.
Thiswork reveals a facile synthesis of gadolinium ions adsorbed 2D-graphitic carbon nitride nanosheets (Gd3+/2D-gCN NSs) via a chemical-adsorption method for supercapacitor electrode materials. The structural, microstructural, and electrochemical properties ofGd3+/2D-gCN NSs and pristine 2D-gCN NSs are ascertained.The calculated capacitance for Gd3+/2D-gCN NSs is almost three times higher than the pristine one. The Nyquist and Bode plots exhibit thecapacitancemechanism.Gd+intercalation between the electrical double layers of adjacent 2D-gCN nanosheets increase the Van der Waals gap, which enhances it's specific capacitance. There is almost 100% retention of capacitance for Gd3+/2D-gCN NSs based device over 1000thcycle.
Display omitted
•Adsorption of NO gas on the pristine, Os, Ir and Pt embedded g-C3N4 monolayers are studied.•The bandgap of the pristine-g-C3N4 monolayer is considerably decreased after the ...decoration of Os, Ir, and Pt on the g-C3N4 monolayer.•The Ir embedded g-C3N4 monolayer has shown the most substantial NO adsorption capacity.•The total magnetic moment of 2.048 μβ is obtained for the Ir embedded g-C3N4 monolayer.•The CDD plots show the charge acceptor nature of the adsorbed NO gas molecule.
In this work, we have studied the adsorption performance of NO gas in the pristine and Os, Ir and Pt embedded g-C3N4 using the density functional theory calculations. It is found that the hexagonal cavity is the most stable site for the embedding of Os, Ir, and Pt on the g-C3N4. The obtained outcomes indicate that NO is physisorbed on pristine g-C3N4 whereas chemisorbed on the Os, Ir, and Pt embedded g-C3N4. The bandgap energy considerably decreases after embedding Os, Ir, and Pt atoms and NO adsorption. Partial density of states plots indicates that embedded metals are a bridge to enhance the hybridization between NO and the g-C3N4. The repositioning of HOMO and LUMO is noticed in the Os, Ir, and Pt embedded g-C3N4. Furthermore, it is observed that Os, Ir, and Pt embedded g-C3N4 are magnetic with total magnetic moments of 3.4037, 2.0476, and 1.6641 μβ correspondingly, which undergoes a significant change after NO adsorption. The Bader charge analysis indicates the acceptor nature of the NO gas molecule further validated the charge density difference calculations. Our calculations reveal that Ir embedded g-C3N4 can be considered an outstanding candidate for sensing NO gas and its elimination from the atmosphere.
Hydrogen bond (HB) interaction is the main driving factor for the nucleation of electroactive β phase within the nonpolar pristine polyvinylidene fluoride (PVDF) and its copolymers when the hydrated ...nitrate salts act as additives. The current work elaborates a density functional theory‐based analysis on the HB interactions within aluminum nitrate nonahydrate‐added polyvinylidene fluoride PVDF/Al(NO3)3∙9H2O, polyvinylidene fluoride‐trifluoro ethylene PVDF‐TrFE/Al(NO3)3∙9H2O, and polyvinylidene fluoride‐hexafluoro propylene PVDF‐HFP/Al(NO3)3∙9H2O composite systems. Polar properties of α (TGTG′) and β (TTTT) phases of the homopolymer and copolymer chains have been compared. Coordination chemistry and formation energies of two stable isomers of Al(NO3)3∙9H2O have been described. Interactions within the polymer/salt complexes have been simulated considering both the salt isomers added to α‐ and β‐tetramer chains of PVDF, PVDF‐TrFE, and PVDF‐HFP. An integral equation formalism polarizable continuum model has been used to replicate the effects of n,n‐dimethyl formamide solvent. HB interaction phenomenon has been described on the basis of electron density difference, interaction energy calculations, symmetry‐adapted perturbation theory, natural bond orbital, Bader's quantum theory of atoms in molecules, delocalization indices, and reduced density gradient analyses. Simulated infra red (IR) and Raman spectra identified the simultaneous presence of CH⋯O (mostly improper) and OH⋯F (mostly proper) HBs between the salt molecule and polymer chains. Correlations among different HB descriptors have been demonstrated to compare the proper and improper nature of the bonds. This research explored some ambiguities in the conventional HB properties, which may be attributed to very low hyperconjugation energies associated with the bonds.
Dispersion‐corrected density functional theory calculations have been performed to describe the proper (red‐shifting) OH⋯F‐ and improper (blue‐shifting) CH⋯O‐type hydrogen bond interactions of two stable configurations of aluminum (Al) nitrate nonahydrate with PVDF, PVDF‐TrFE, and PVDF‐HFP. Hydrated Al nitrate has been found to exhibit a stronger interaction with polar β‐phases, compared to nonpolar α‐phases of the homopolymer and copolymer chains. Interfragment noncovalent interactions have been elucidated by interaction energy calculations and different quantum chemical hydrogen bond descriptors.
Density functional theory (DFT) is used to find out the effect of platinum and phosphorus doping (as individuals and together) on the structural, electronic as well as optical performance of ...heptazine based graphitic carbon nitride (g-C
3
N
4
) monolayer. The calculated bandgap value for the pristine g-C
3
N
4
is 1.2 eV. In the case of Pt doping delocalization of the frontier molecular orbitals (MO) are not adequate, but P doping as individual and together with Pt results in strong delocalization of frontier MOs. Pt and P co-doping provides two new paths, for the relocation of photogenerated charge carriers between adjacent heptazine units.
Furthermore, there is a magnified optical absorption in the ultraviolet as well as the infrared region and improved electronic movement in co-doped g-C
3
N
4
. Optical conductivity is enhanced by approximately 40% at 200 nm after the co-doping. A decrease in the work function value is also observed in doped g-C
3
N
4
with the minimum amount for Pt and P co-doping. Thus Pt/P co-doping process may be considered as a tool to upgrade the photocatalytic performance of g-C
3
N
4
monolayer.
Finding proper candidates for polymer-supported ionic liquid (IL)-based gas separating membranes is a challenge. The current article elucidates the quantum chemical perspective of the selective gas ...adsorption efficiency, from a mixture of CO2, CO, CH4, and H2, of α- and β-polyvinylidene fluoride (PVDF)-supported imidazolium- and pyridinium-based six ionic liquid membranes. Although IL-based membrane efficiency mainly depends on the gas solubility of ILs, IL/support binding and gas adsorption on the support material are also studied to describe the overall gas adsorption properties of the PVDF/IL complexes. β-PVDF exhibits better binding with the ILs, and better gas affinity, thus, qualified as a more suitable membrane component as compared to α-PVDF. Dispersion-corrected density functional calculations are performed to provide a detailed insight into the energetic interactions, nonbonding intermolecular interactions based on symmetry adapted perturbation theory (SAPT), natural bond orbitals (NBO), Bader's quantum theory of atoms in molecules (QTAIM), reduced density gradient (RDG), frontier orbital interactions, density of states (DOS), and thermochemical analyses of the gas-adsorbed systems. Gas molecules interact with the membrane components through weak hydrogen bonds and exhibit low interaction energies, indicating physisorption of the gases. Gas adsorption energies are more negative than the mutual interaction energies of the gas molecules, ensuring effective gas adsorption by the membrane components. All the β-PVDF/IL systems have shown the highest and lowest affinity for CO2 and H2, respectively, leading to effective separation of CO2 and H2 from the other gases.
Display omitted
•DFT analyses demonstrate selective gas adsorption by PVDF/IL membranes.•Inter-unit binding of α-PVDF/IL and β-PVDF/IL is compared.•Weak hydrogen bond interactions among the membrane components and gas molecules correspond to physisorption of the gases.•Temperature dependence of gas selectivity (CO2/CO, CO2/CH4, CO2/H2, CO/H2, CH4/H2, and CO/CH4) of membranes is derived.
We have explored the consequence of lithium and phosphorous functionalization on the graphitic carbon nitride (g-C3N4) monolayer for hydrogen storage using density functional theory. Both pristine ...and Li and P decorated g-C3N4 show a semiconductor nature. The substantial overlap between the s orbital of Li and the p orbital of nitrogen near the Fermi level shows the binding between Li and the g-C3N4. The repositioning of HOMO and LUMO is noticed in the Li and P decorated g-C3N4. The Bader charge analysis indicates the charge allocation from the Li and P atom to the g-C3N4, which results in the adsorption of H2 by electrostatic interaction. The hydrogen storage capacity of 5.78 wt% is obtained after functionalizing Li and P into the g-C3N4. The obtained adsorption energies for the H2 adsorption and the H2 desorption temperature confirm that Li and P functionalized g-C3N4 is a fascinating candidate for the reversible loading of H2 at ambient conditions.
Display omitted
•The adsorption of H2 on the Li and P functionalized g-C3N4 is studied using DFT.•Li and P addition results in a decrease in the band gap of the pristine-g-C3N4.•A gravimetric hydrogens storage capacity of 5.78 wt% is obtained for Li/P-g-C3N4.•The binding properties of the adsorbed H2 are typical for physisorption.
Modifications of electronic and optical properties due to platinum, silicon, and platinum-silicon co-doping in the graphitic carbon nitride (g-C3N4) monolayer have been explored through density ...functional theory (DFT). The bandgap value of 1.2 eV has been obtained for the pristine g-C3N4 using generalized gradient approximation (GGA) employing Perdew-Burke-Ernzerhof (PBE) functional. The doping process has resulted in a fall in bandgap value. The platinum-silicon co-doping into g-C3N4 provides two new paths, C–N–Pt–N–C, and C–N–Si–N–C for the relocation of electron-hole couples across the adjacent heptazine rings. There is approximately a 25% increment (at 1 eV) in the optical conductivity in the infrared region after co-doping. The co-doped g-C3N4 also shows enriched light absorption. The work function is found to be decreased from 4.29 eV for the pristine g-C3N4 to 3.58 eV for the Pt/Si-co-doped g-C3N4. Hence, platinum-silicon co-doping should be considered as a suitable means to advance the photocatalytic performance of g-C3N4.
Display omitted
The use of copper in the modern energy sector is expected to grow five times as the sector transitions from the traditional power generation of nuclear and fuel-based systems to renewable energy. In ...industries, copper's high conductivity and excellent oxidation resistance are utilized in the extreme environments of heat exchangers and cooling systems. To handle the sharp thermal gradients and sudden temperature changes in those conditions, copper alloys need adequate thermal shock resistance. Hence, its optimization is crucial for the development of these alloys. In this study, a dataset of 2198 copper alloys was collected for thermal shock resistance prediction. Models based on six machine learning algorithms were prepared using composition and manufacturing processes as features. The model based on the multi-layer perceptron algorithm achieved an accuracy of 0.89
R
2
scores. Further analysis was done to study the effects of different alloying elements and manufacturing processes with the help of correlation heatmaps and sequential feature selectors. Alloying additions of nickel, aluminum, and silicon and heat-treatment processes of hardening and precipitation hardening were found to be most effective in boosting the thermal shock resistance.
