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Expression of concern for 'Designing novel morphologies of L -cysteine surface capped 2D covellite (CuS) nanoplates to study the effect of CuS morphologies on dye degradation rate under visible light' by Shahid Iqbal et al., CrystEngComm, 2020, 22, 4162–4173, https://doi.org/10.1039/D0CE00421A. [ABSTRACT FROM AUTHOR]

The construction of photocatalytic systems that have strong redox capability, effective charge separation, and large reactive surfaces is of great scientific and practical interest. Herein, an edge‐connected 2D/2D Z‐scheme system that combines the facet junction and the interfacial heterojunction to achieve effective long‐range charge separation and large reactive surface exposure is designed and fabricated. The heterostructure is realized by the selective growth of 2D‐layered MoS2 nanoflakes on the edge‐sites of thin TiO2 nanosheets via an Au‐promoted photodeposition method. Attributed to the synergetic coupling of the facet junction and the interfacial heterojunction that assures the effective charge separation, and the tremendous but physically separated reactive sites offered by layered MoS2 and highly‐exposed (001) facets of TiO2, respectively, the artificial Z‐scheme exhibits excellent photocatalytic performance in photodegradation tests. Moreover, the junctional plasmonic Au nanoclusters not only act as electron traps to promote the edge‐selective synthesis but also generate "hot electrons" to further boost photocatalytic performance. The Z‐scheme charge‐flow direction in the heterostructure and the roles of electrons and holes are comprehensively studied using in situ irradiated X‐ray photoelectron spectroscopy and photodegradation tests. This work offers a new insight into designing high‐performance Z‐scheme photocatalytic systems. [ABSTRACT FROM AUTHOR]

Two-dimensional materials have gained immense attention for technological applications owing to their characteristic properties. MXene is one of the fast-growing family of 2D materials that exhibits remarkable physiochemical properties that cater numerous applications in the field of energy and storage. This review comprises the significant advancement in the field of 2D MXene and discusses the evolution of the design, synthetic strategies, and stability. In addition to illuminating the state-of-the-art applications, we discuss the challenges and limitations that preclude the scientific fraternity from realizing functional MXene with controlled structures and properties for renewable clean energy conversion and storage applications. [ABSTRACT FROM AUTHOR]

The efficient market hypothesis (EMH) forms the basis of classical financial theories, assuming the rationality of investors. However, this hypothesis often proves inadequate in financial markets due to investors' tendency toward irrational behaviour. Behavioural finance investigates how individual investors analyse and interpret information when making investment decisions. This study explores the relationship between behavioural factors and investment decision-making, considering the moderating effect of COVID-19. Using convenient sampling and structured questionnaires, the researcher collects data from 364 investors actively trading on the Pakistan Stock Exchange. Structural Equation Modelling (SEM) with Smart PLS 4 software is employed as the research method to assess the influence of independent variables on the dependent variable, moderated by COVID-19. This research aims to encourage investors to carefully consider their decisions before investing and understand how psychological factors may impact their investment choices. The findings indicate a positive association between behavioural factors and investment decision-making, alongside a negative impact of COVID-19. This study is beneficial for both individual and institutional investors as it underscores the importance of behavioural factors (herding, loss aversion, and risk perception) in investment decision-making within the context of Pakistani investors. [ABSTRACT FROM AUTHOR]

As the most representative member of a new emerging family of 2D material, titanium carbides or nitrides (MXenes), Ti3C2Tx and its 2D assembly format, Ti3C2Tx film, have displayed outstanding performance in a broad range of practical applications. However the mechanical behaviors of Ti3C2Tx films are rarely reported. We report a systematic study of the tensile behavior of Ti3C2Tx films. Ti3C2Tx films with various thicknesses (2–17 µm) were prepared by the vacuum filtration method. Quasi-static tension and cyclic tension tests were performed to investigate the deformation and fracture mechanism of Ti3C2Tx films. It was found that: (1) the relative sliding between Ti3C2Tx flakes is the dominant deformation mechanism of Ti3C2Tx films. Cyclic loading-releasing in tension suppresses the inter-layer sliding of Ti3C2Tx flakes effectively and thus the tensile strength of thicker Ti3C2Tx film (5 µm) film improves from 57 MPa to 67 MPa. (2) The mechanical properties of Ti3C2Tx films are found to be thickness dependent. When the film thickness increases from 2.3 to 17 µm, the tensile strength and elastic modulus drop from 61 to 36 MPa and from 17 to 8 GPa, respectively. This is interpreted as more structural defects presented in the through-the-thickness direction as film thickness is increased. (3) Moderate ultrasonication pretreatment (30 min) reduces the Ti3C2Tx flake size significantly while improving the compactness of the Ti3C2Tx film; and the resulting Ti3C2Tx film shows a linear stress-strain relationship without plastic-like deformation. As a result, the tensile strength of 5 µm thick Ti3C2Tx film is enhanced to 85 MPa; (4) Structural defects of the Ti3C2Tx film have significant effects on both the brittle-like fracture behavior and the distribution of tensile strength. [ABSTRACT FROM AUTHOR]

Pure self-assembled L -cysteine stabilized covellite nanoplates (CuS@ L -Cys NPs) with the best control over size, phase purity structure, morphology, and electrochemical properties were synthesized using a facile, template-free hydrothermal route. The effects of temperature (100–180 °C), reaction time (8–24 h), pH of reaction medium (7–14), concentration of base (0.1–2.4 mL NH3) and concentration of thiourea (1–4 mmol) on the morphologies of CuS@ L -Cys nanoplates were studied. The photocatalytic performance of CuS@ L -Cys NPs under visible light was studied using methyl orange (MO) as a model dye. CuS@ L -Cys NPs were reused successfully for the photodegradation of dye due to the recycling ability of CuS@ L -Cys NPs. The hydroxyl radicals (˙OH) generated by CuS@ L -Cys NPs were detected using terephthalic acid (TA) as a probe molecule through the photoluminescence (PL) technique. The successful capping of L -Cys on the surface of CuS NPs was confirmed by FTIR spectroscopy. The BET surface areas of the hexagonal CuS@ L -Cys NPs and oblong CuS@ L -Cys NPs were measured to be 11.87 and 5.66 m2 g−1, respectively. The optical band gaps of the hexagonal CuS@ L -Cys NPs (2.0 eV) and oblong CuS@ L -Cys NPs (2.04 eV) were determined according to direct bandgap calculations. These results support the presence of hexagonal CuS@ L -Cys NP catalysts as efficient accelerators of the photodegradation of MO. Furthermore, the L -cysteine (L -Cys) protective layer could efficiently alleviate the photocorrosion of CuS, giving rise to excellent stability. The high photocatalytic activity of the hexagonal CuS@ L -Cys NPs can be ascribed to the reduction of photoinduced electron–hole pair recombination and high specific surface area, as confirmed by BET for other representative samples. [ABSTRACT FROM AUTHOR]

Galvanic replacement is a versatile method of converting simple noble metallic nanoparticles into structurally more complex porous multimetallic nanostructures. In this work, roughened nanoporous Ag-Au bimetallic triangular nanoprisms (TNPs) are synthesized by galvanic replacement between smooth Ag triangular plates and AuCl4− ions. Transmission electron microscope and the elementary mapping measurements show that numerous protrusions and pores are formed on the {111} facets, and Ag and Au atoms are homogeneously distributed on the triangular plates. Due to the additional “hot spots” generated by the surface plasmon coupling of the newly formed protrusions and pores, the roughened nanoporous Ag-Au TNP aggregates demonstrate a higher surface-enhanced Raman scattering enhancement factor (seven times larger) and better reproducibility than that of smooth Ag triangular particle aggregates. These synthesized roughened nanoporous Ag-Au bimetallic TNPs are a promising candidate for the applications in analytical chemistry, biological diagnostics, and photothermal therapy due to their excellent plasmonic performances and good biocompatibility. [ABSTRACT FROM AUTHOR]

Freestanding electrode 3D architectures, based on Ni(OH)2 nanosheets grown on a joint‐welded carbon nanotube foam network, are introduced via a unique and facile chemical bath synthesis strategy. As a result of the unique 3D core configuration of nanotubes and the nanostructural shell design of Ni(OH)2 nanosheets, the prepared electrode displays an excellent electrochemical performance. The electrode shows an outstanding specific capacitance of 1272 F g−1 at a scan rate of 2 A g−1, and it even retained a value of 517 F g−1 at a scan rate of 20 A g−1. The excellent electrochemical performance is due to the highly conductive nanotube network and the unique nanostructure of Ni(OH)2 nanosheets, which promote the ion transport in fast speed, while facilitate the charge storage via redox reactions in nanosheets. The large specific capacitance and superior rate performance of core–shell Ni nanosheets, combined with the elasticity of the welded‐nanotube network, render these 3D architectures as promising candidates of freestanding electrodes for high‐performance flexible supercapacitor applications. [ABSTRACT FROM AUTHOR]