Recent progress in preparation of branched polyethylene with nickel, titanium, vanadium and chromium catalytic systems and EPR study of related catalytic systems

Highly Active Oxygen Evolution Reaction of NiMoO4 Sub-1 nm Nanowires Boosts Luminol Electrochemiluminescence

In recent years, there has been an increasing research focus on the luminol-H2O electrochemiluminescence (ECL) system due to its ability to address the instability and toxicity of H2O2, which are common issues associated with the conventional luminol-H2O2 ECL system. To enhance the ECL efficiency of the luminol-H2O system, researchers have developed electrocatalytic materials with exceptional oxygen evolution reaction (OER) properties to facilitate water electrolysis into O2 to produce reactive oxygen species (ROS) and act as co-reactant promoters. However, most of these materials are characterized by their nanoscale or microscale dimensions, resulting in relatively large sizes and low specific surface areas, which hinder the application of the luminol-H2O system. To address this challenge, nickel molybdate sub-1 nm nanowires (NiMoO4 S1 NWs) with a large specific surface area is synthesized that can offer many active sites to enhance the performance of the OER to boost the ECL of luminol. This study demonstrates that the large amount of ROS generated by the OER of NiMoO4 S1 NWs play a crucial role in enhancing the ECL intensity of luminol. Finally, a NiMoO4 S1 NWs-based ECL biosensor for the highly sensitive detection of the nucleocapsid proteins of SARS-CoV-2 is successfully constructed.

A review on identification, quantification, and transformation of active species in SCR by EPR spectroscopy

Electron paramagnetic resonance (EPR) is the only technique that provides direct detection of free radicals and samples that contain unpaired electrons. Thus, EPR had an important potential application in the field of selective catalytic reduction of nitrogen oxide (SCR). For the first time, this work reviewed recent developments of EPR in charactering SCR. First, qualitative analysis focused on recognizing Cu, Fe, V, Ti, Mn, and free-radical (oxygen vacancy and superoxide radical) species. Second, quantification of the active species was obtained by a double-integral and calibration method. Third, the active species evolved because of different thermal treatments and redox-thermal processes under reductants (NH₃ and NO). The coordination information of the active species in catalysts and their effects on SCR performances were concluded from mechanism viewpoints. Finally, potential perspectives were put forward for EPR developments in characterizing the SCR processes in the future. After all, EPR characterization will help to have a deep understanding of structure-activity relationship in one catalyst.