Cu2MoS4 Nanocatalyst-Based Electrochemical Sensor for Ofloxacin Electro-Oxidation: Delineating the Combined Roles of Crystallinity and Morphology on the Analytical Performance

In this study, we demonstrate the influence of crystallinity and morphology on the analytical performance of various Cu2MoS4 (CMS) nanocatalysts-based electrochemical sensors for the high-efficiency detection of Ofloxacin (OFX) antibiotic. The electrochemical kinetics parameters including peak current response (ΔIp), peak-to-peak separation (ΔEp), electrochemically active surface area (ECSA), electron-transfer resistance (Rct), were obtained through the electrochemical analyses, which indicate the single-crystalline nature of CMS nanomaterials (NMs) is beneficial for enhanced electron-transfer kinetics. The morphological features and the electrochemical results for OFX detection substantiate that by tuning the tube-like to plate-like structures of the CMS NMs, it might noticeably enhance multiple adsorption sites and more intrinsic active catalytic sites due to the diffusion of analytes into the interstitial spaces between CMS nanoplates. As results, highly single-crystalline and plate-shaped morphology structures of CMS NMs would significantly enhance the electrocatalytic OFX oxidation in terms of onset potential (Eonset), Tafel slope, catalytic rate constant (kcat), and adsorption capacity (Γ). The CMS NMs-based electrochemical sensing platform showed excellent analytical performance toward the OFX detection with two ultra-wide linear detection concentration ranges from 0.25-100 and 100-1000 μM, a low detection limit of 0.058 μM, and an excellent electrochemical sensitivity (0.743 μA μM-1 cm-2).

Z-scheme Cu2MoS4/CdS/In2S3 nanocages heterojunctions-based PEC aptasensor for ultrasensitive assay of fumonisin B1 via signal amplification with hollow PtPd–CoSnO3 nanozyme

Fumonisin B1 (FB1), the most prevalent and highest toxicity mycotoxins among fumonisins family, poses threats to human especially children and infants even at a trace level. Therefore, its facile and sensitive detection is of importance. Herein, Z-scheme Cu₂MoS₄/CdS/In₂S₃ nanocage-like heterojunctions (labeled Cu₂MoS₄/CdS/In₂S₃) were synthesized, whose photoelectrochemical (PEC) property and electron transfer mechanism were strictly investigated. The Cu₂MoS₄/CdS/In₂S₃ behaved as photoactive substrate for building a PEC sensing platform for detection of FB1, integrated with PtPd alloy modified hollow CoSnO₃ nanoboxes (labeled PtPd-CoSnO₃) nanozyme. By virtue of the stronger affinity between the target FB1 and its aptamer (FB1-Apt), the photocurrent was recovered by releasing the CoSnO₃-PtPd₃ modified FB1-Apt (FB1-Apt/PtPd-CoSnO₃) from the photoanode, which can terminate the catalytic precipitation reaction for its peroxidase-like property. The resultant PEC aptasensor exhibited a wider dynamic linear range from 1 × 10^-4 to 1 × 10² ng mL^-1 with a lower limit of detection (0.0723 pg mL^-1). Thus, this research provides a feasible PEC sensing platform for routine analysis of other mycotoxins in practice.

MXene-supported copper-molybdenum sulfide nanostructures as catalysts for hydrogen evolution

The synthesis and enhanced HER performance of Cu2MoS4/Ti3C2Tx-30% was demonstrated.

Investigation on the Growth Mechanism of Cu2 MoS4 Nanotube, Nanoplate and its use as a Catalyst for Hydrogen Evolution in Water

Cu₂ MoS₄ is a ternary transition-metal sulfide that shows great potential in the field of energy conversion and storage, namely catalytic H₂ evolution in water and Li-, Na- or Mg-ion battery. In this work, we report on a growth mechanism of the single-crystalline Cu₂ MoS₄ nanotube from (NH₄ )₂ MoS₄ salt and Cu₂ O nanoparticle. By probing the nature and morphology of solid products generated in function of reaction conditions we find that the crystalline Cu(NH₄ )MoS₄ nanorod is first generated at ambient conditions. The nanorod is then converted into Cu₂ MoS₄ nanotube under hydrothermal treatment due to the Kirkendall effect or a selective etching of the Cu₂ MoS₄ core. Extending the hydrothermal treatment causes a collapse of nanotube generating Cu₂ MoS₄ nanoplate. The catalytic activities of these sulfides are investigated. The Cu₂ MoS₄ shows superior catalytic activity to that of Cu(NH₄ )MoS₄ . Catalytic performance of the former largely depends on its morphology. The nanoplate shows superior catalytic activity to the nanotube, thanks to its higher specific electrochemical surface area.