Superior catalytic performance and CO tolerance of PtCu/graphdiyne electrocatalyst toward methanol oxidation reaction

Surfactant-free CuxPty nano-alloys with controllable atomic ratios and their enhanced electrocatalytic activity

The electrocatalytic mechanisms of electrocatalysts were constrained by the disparities between the genuine catalytic interface and construction interface. This work demonstrated the relationship between the CuxPty nano-alloy atomic ratios and their catalytic performance. Firstly, we developed a facile synthesis of surfactant-free CuxPty nano-alloys with tunable Cu atomic ratios (ranging from 35 to 72 at%) under ambient conditions. Considering no surfactant-free was applied, surface active sites were uncovered, which was beneficial to ensured consistency between the calculated interface and the actual interface. Based on the experiment and calculation, the relationship between the Pt loading rate and electrocatalytic activity of CuxPty nano-alloy toward hydrogen evolution reaction (HER) was systematically investigated. Under the acidic media, the over-potential by Cu72Pt28 was 7.17 mV, which was 11.5% by the pure Pt nano-particles (NPs). The lower over-potential could be derived from a favorable d-band center of Cu72Pt28, which accelerated the adsorption and desorption of H+. The correlation between the d-band center and the electrocatalytic activity of CuxPty nano-alloy was investigated. Benefiting from the surfactant-free surface, the CuxPty nano-alloy exhibited a favorable electrocatalytic activity toward methanol detection. With the increase in methanol concentration, the anodic peak for methanol oxidation was linearly increased. The linear relationship endowed the CuxPty nano-alloy with a favorable sensor performance. It is suggested that the CuxPty nano-alloy with a higher Pt atomic ratio showed a wider detection range and the CuxPty nano-alloy with a higher Cu atomic ratio showed an enhanced sensitivity. The superior sensor performances could also be utilized for ethanol detection. This work demonstrated the favorable performance of the surfactant-free CuxPty nano-alloy toward hydrogen generation and alcoholic solution (methanol and ethanol) detection. Considering the experiential results were agreed well with calculation, this work pave the way for designing cost-effective electrocatalysis by optimizing its d band center and maximized active sites.

Modification Strategies for Development of 2D Material-Based Electrocatalysts for Alcohol Oxidation Reaction

2D materials, such as graphene, MXenes (metal carbides and nitrides), graphdiyne (GDY), layered double hydroxides, and black phosphorus, are widely used as electrocatalyst supports for alcohol oxidation reactions (AORs) owing to their large surface area and unique 2D charge transport channels. Furthermore, the development of highly efficient electrocatalysts for AORs via tuning the structure of 2D support materials has recently become a hot area. This article provides a critical review on modification strategies to develop 2D material-based electrocatalysts for AOR. First, the principles and influencing factors of electrocatalytic oxidation of alcohols (such as methanol and ethanol) are introduced. Second, surface molecular functionalization, heteroatom doping, and composite hybridization are deeply discussed as the modification strategies to improve 2D material catalyst supports for AORs. Finally, the challenges and perspectives of 2D material-based electrocatalysts for AORs are outlined. This review will promote further efforts in the development of electrocatalysts for AORs.

Low-temperature N-anchored ordered Pt3Co intermetallic nanoparticles as electrocatalysts for methanol oxidation reaction

To enhance nanocatalyst performance and durability for the methanol oxidation reaction (MOR) in a direct methanol fuel cell, small-sized (2.1 nm) and structurally ordered Pt₃Co intermetallic nanoparticles are uniformly anchored onto nitrogen-doped carbon nanotubes (N-CNTs) via a low-temperature N-anchoring method, and the N-doping abilities of different N-containing reagents are compared. After investigating the microstructure of Pt₃Co/N-CNTs and evaluating their catalytic activity for the MOR, the results show that N-doping facilitates the uniform loading of Pt₃Co NPs and plays a crucial role in improving the electrocatalytic activity of Pt₃Co NPs supported on CNTs. Pt₃Co/N-CNT-M with melamine as the N dopant exhibits the highest MOR activity and stability among all N-CNT-supported Pt₃Co NPs and Pt/N-CNT-M. Density functional theory calculations suggest that the doping of N enhances the binding energy of CNTs to Pt₃Co NPs, and the MOR mechanism shows that the introduction of Co is the reason for the enhancement of MOR reaction kinetics. The excellent electrochemical performance of Pt₃Co/N-CNT-M is mainly attributed to the synergistic effect of N and Pt₃Co intermetallic nanoparticles. The combination of ordered alloy nanoparticles and high-performance carrier N-CNT-M described herein exhibits great potential for fuel cells and may provide an unequivocal direction for the optimization of catalyst performance.

Phosphorus-modified two-dimensional graphdiyne (CnH2n-2)/ZnCdS forms S-scheme heterojunctions for photocatalytic hydrogen production

Graphdiyne (GDY) is a new type of carbon allotrope material with a network structure composed of sp- and sp²-hybridized carbon, and its excellent photoelectrochemical properties have an extraordinary impact on energy materials. In this work, a graphite alkyne material was calcined and used as an anchor substrate to fix bimetallic sulfide-zinc-cadmium sulfide to form a phosphorus-doped graphdiyne (GDY-P)/zinc-cadmium sulfide (ZnCdS) heterojunction photocatalyst. The close contact between the 2D/0D binary heterojunction interfaces produced a strong interfacial force, and the final hydrogen evolution rate of the GDY-P/ZnCdS structure reached 10 395.57 μmol g^-1 h^-1, which was 2.57 and 240 times those of ZnCdS and GDY, respectively. The S-scheme heterojunction constructed by GDY-P and ZnCdS accelerates the formation of electron-hole pairs, improves the utilization of strongly reduced electrons, and overcomes the self-agglomeration of ZnCdS, ensuring the high hydrogen evolution activity of the binary structure. This work provides a new application paradigm for the construction of S-scheme heterojunctions for hydrogen evolution using new carbon materials in the field of photocatalysis.

AuAg nanocages/graphdiyne for rapid elimination and detection of trace pathogenic bacteria

We prepared a biocompatible AuAg nanocages/graphdiyne @ polyethylene glycol (AuAg/GDY@PEG) composite. The combination of AuAg and GDY to obtain a synergistically enhanced photothermal effect, and the antibacterial effect of GDY and AuAg are used in combined anti-infective therapy. The in vitro antibacterial activity of AuAg/GDY@PEG was investigated, showing an impressive broad-spectrum antibacterial activity with the killing rate > 99.999%. Based on the photothermal conversion ability of AuAg/GDY@PEG, a simple photothermal immunoassay for pathogenic bacteria was successfully established. Sandwich immune response was performed on a microporous plate, the microplate containing the antibody binds specifically to the bacterium being tested, which then binds to the material with the antibody on its surface, and the signal was a change in temperature under 808 nm near-infrared light. The limit of detection (LOD) for S. typhimurium detection is 10³ CFU mL^-1, with a range of 10³-10⁷ CFU mL^-1. This method is accurate, rapid and low-cost, which can be used for on-site detection of pathogenic bacteria in food.