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Dichlorodiphenyltrichloroethane (DDT), hexachlorocyclohexane (BHC), aldrin, and chlordimeform are ubiquitous organochlorine pesticide (OCP) residues in the environment, which pose a great threat to human health and ecosystems due to their high toxicity and easy accumulation. Based on the density functional theory (DFT) calculations, a two-dimensional InP 3 monolayer was selected as a sensing material to study the sensitivity detection and adsorption behaviors toward BHC, aldrin, chlordimeform, and DDT. The calculation results show that four pesticide molecules are adsorbed on the InP 3 surface by physical interaction. The identified response values (69.1, -43.1%) for DDT and chlordimeform reveal the potential of the InP 3 monolayer as a sensing material for the detection of these two pesticides, accompanied by the achievement of cyclic utilization by heating to 498 K. The most satisfactory result is the adsorption of BHC, owing to the admirable sensing response (62.7%) and short recovery time (1.8 s) at room temperature, which makes InP 3 a promising pesticide sensor for BHC. However, the InP 3 surface is unsuitable for aldrin sensing due to poor response (-1.9%). Our work gives theoretical insight into the good sensitivity and recycling of the InP 3 monolayer as a new pesticide sensor to detect DDT, BHC, and chlordimeform, which further broadens the application prospect of the InP 3 nanosheet into the sensitive detection of organochlorine pesticides in the ecological environment., Competing Interests: The authors declare no competing financial interest., (© 2023 The Authors. Published by American Chemical Society.)

The bifunctional efficient electrocatalysts for both hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) are in urgent need for the advanced overall water splitting (OWS) device. Restricted by the thermodynamic limitations of the catalytic active center for OER and the reaction kinetics limitations induced by the structure of the electrocatalysts, the development of OWS catalysts requires more effort. Herein, a porous carbon-based bimetal electrocatalyst of Mo 0.84 Ni 0.16 -Mo 2 C@NC nanosphere is prepared by hydrothermal treatment of PMo 12 @PVP@Zn/Ni-ZIF which is synthesized via one-pot self-assembled hydrothermal method. Our study confirms that the Mo-Ni alloy and Mo 2 C nanoparticles homogeneously distribute in nitrogen-rich carbon-based materials. Furthermore, the porous structure exposes rich active sites and increases the effective specific area for redox reactions. The obtained Mo 0.84 Ni 0.16 -Mo 2 C@NC catalyst requires low overpotentials of 151 and 285 mV to reach a current density of 10 mA cm -2 towards the water reduction and oxidation in 1 M KOH solution, respectively, and possesses good catalytic stability for one day. This work introduces an advanced method for the synthesis of the bimetal electrocatalyst., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2021. Published by Elsevier Inc.)

The development of outstanding noble-metal-free electrocatalysts for the hydrogen evolution reaction (HER) has attracted broad interest. Herein, a novel one-dimensional (1D) HER hybrid catalyst consisted of cobalt phosphide (CoP) and molybdenum carbide (Mo 2 C) nanoparticles wrapped by nitrogen-doped graphitic carbon (called CoP/Mo 2 C-NC) was successfully fabricated by a facile continuous-flow method and a simple two-step annealing process. During these processes, the successful synthesis of the MoO 3 nanorods coated with cobalt zeolitic imidazolate frameworks (Co-ZIF-67) (Co-ZIF-67@MoO 3 ) through the continuous-flow method plays a key role. The as-synthesized CoP/Mo 2 C-NC hybrid electrocatalyst exhibits a significantly enhanced HER electrocatalytic activity over the entire pH range relative to that of the control materials CoP, Mo 2 C-NC, and physically mixed CoP and Mo 2 C-NC. The outstanding HER catalytic performance is mainly due to the fact that the electron cloud transfers from Co to Mo in CoP/Mo 2 C-NC through the Co-P-Mo bond, resulting in the formation of a high valence state for Co (Co 3+ ) species and lower valence states for Mo (i.e., Mo 2+ , Mo 3+ ) species, providing the abundant HER active sites. Moreover, the Gibbs free energy (Δ G H* ) of CoP/Mo 2 C-NC obtained by the density function theory calculations indicates a good balance between the Volmer and Heyrovsky/Tafel steps in HER kinetics. Such a cobalt zeolitic imidazolate framework-mediated strategy depicted in this work offers an interesting perspective for developing highly efficient noble-metal-free electrocatalysts for hydrogen production.

The exploration of highly efficient and stable bifunctional electrocatalysts for overall water splitting is currently of extreme interest for the efficient conversion of sustainable energy sources. Herein, we provide an earth-abundant, low-cost, and highly efficient bifunctional electrocatalyst composed of cobalt sulfide (Co 9 S 8 ) and molybdenum carbide (Mo 2 C) nanoparticles anchored to metal-organic frameworks (MOFs)-derived nitrogen, sulfur-codoped graphitic carbon (Co 9 S 8 -NSC@Mo 2 C). The new composite mode of the electrocatalyst was realized through simple pyrolysis processes. The composite electrocatalyst shows outstanding hydrogen evolution reaction (HER) performance and excellent stability over the entire pH range. For example, it has a lower overpotential of 74, 89, and 121 mV with the Tafel slopes of 69.3, 86.7, and 106.4 mV dec -1 to achieve a current density of 10 mA cm -2 in 0.5 M H 2 SO 4 , 1.0 M KOH, and 1.0 M phosphate-buffered saline solutions, respectively. Moreover, it shows a small overpotential of 293 mV with a Tafel slope of 59.7 mV dec -1 to reach 10 mA cm -2 for the oxygen evolution reaction (OER) in 1.0 M KOH. The significantly enhanced HER and OER activities of Co 9 S 8 -NSC@Mo 2 C are mainly attributable to the electron transfer from Co to Mo 2 C, resulting in a lower Mo valence and a higher Co valence in Co 9 S 8 -NSC@Mo 2 C. Furthermore, using the Co 9 S 8 -NSC@Mo 2 C bifunctional electrocatalyst as both the anode for the OER and the cathode for the HER for overall water splitting, a cell voltage of only 1.61 V is needed to derive a current density of 10 mA cm -2 . This interesting work offers a general method for designing and fabricating highly efficient and stable non-noble electrocatalysts for promising energy conversion.