Understanding and exploring the decisive factors responsible for superlative catalytic efficiency is necessary to formulate active electrode materials for improved electrocatalysis and high-throughput sensing. This research demonstrates the ability of bud-shaped gold nanoflowers (AuNFs), intermediates in the bud-to-blossom gold nanoflower synthesis, to offer remarkable electrocatalytic efficiency in the oxidation of ascorbic acid (AA) at nanomolar concentrations. Multicomponent sensing in a single potential sweep is measured using differential pulse voltammetry while the kinetic parameters are estimated using electrochemical impedance spectroscopy. The outstanding catalytic activity of bud-structured AuNF [iAuNFp(Bud)/iGCp ≅ 100] compared with other bud-to-blossom intermediate nanostructures is explained by studying their structural transitions, charge distributions, crystalline patterns, and intrinsic irregularities/defects. Detailed microscopic analysis shows that density of crystal defects, such as edges, terraces, steps, ledges, kinks, and dislocation, plays a major role in producing the high catalytic efficiency. An associated ab initio simulation provides necessary support for the projected role of different crystal facets as selective catalytic sites. Density functional theory corroborates the appearance of inter- and intra-molecular hydrogen bonding within AA molecules to control the resultant fingerprint peak potentials at variable concentrations. Bud-structured AuNF facilitates AA detection at nanomolar levels in a multicomponent pathological sample.

Polyvinylpyrrolidone (PVP)-based silver nanoprisms (AgNPrs) show an initial stacking geometry because of their low zeta potential and electrostatic interaction between face-to-face energetically stable {111} surface-bound pyrrolidone groups through the Na + -ioninduced cation−π interaction. Congested interplanar space between AgNPrs allows As(III) to react differentially with silver atoms from facial {111} and peripheral {110} facets to result in smaller stackings and finally nanoseeds. Above this critical concentration of As(III), PVP leached out from nanoparticles to form nanoseed-engulfed emulsions and induced controlled aggregation. This entire morphological transition has been decoded by recording their surface plasmon and surfaceenhanced Raman scattering tuning and confirmed by the transmission electron microscopy study. Strong affinity and selectivity of As(III) toward the Ag atom (verified and estimated by the HF/3-21g* level of density functional theory calculation) coupled with low-cost colorimetry provide us a versatile assay with potential application in the environmental protection drive.

With an increasing demand for clean and sustainable energy which is directly related to water splitting, regenerative fuel cells, metal-air batteries, etc., exploring an efficient and inexpensive electrocatalyst with highly stable for oxygen evolution reaction (OER) is very important. In this article, here we demonstrated the nanorod Zn-Co-Te, is found to be a very good electrocatalyst for oxygen evolution reaction (OER) in alkali medium (KOH, pH = 15.14) with onset potential 1.38 V vs RHE. When this catalyst used as an electrocatalyst Zn-Co-Te nanorod obtained low overpotential 221 mV at a 10 mAcm−2 current density with Tafel slope 91 mV/dec and high stability within three months.

A void-enriched and highly strained porous Au−Ag nanoalloy (NP alloy ) has been synthesized from Au−Ag core−shell nanostructure by employing a galvanic replacement reaction and introducing Kirkendall voids in it. Obtained NP alloy acts both as an efficient cathodic and anodic material for methanol, ethylene glycol, and glycerol oxidation as well as oxygen reduction reactions simultaneously in an alkaline medium. High catalytic efficacy (low onset potential (E on ) and high current density (j)), wide thermal stability, and positive alcohol tolerance response of NP alloy sets them as a practical bifunctional electrode coating alternative compared to Pt/C in designing an efficient alkaline direct alcohol fuel cell.

This report quantitatively investigates the role of grain-boundary and grain size in the excellent electrocatalytic activity of our recently synthesized shape-engineered (bud-shaped AuNP50 to bloom or flower-shaped AuNP75 to over-bloomed AuNP150) and differential grain-boundary enriched anisotropic flower-like gold nanostructures for the hydrogen evolution reaction (HER). All the synthesized anisotropic gold nanoparticles (AnGNPs) and especially the AuNP75 exhibit outstanding catalytic activities (in terms of both overpotential and turnover frequency) toward HER in different pH media compared to that of normal spherical-shaped gold nanoparticles (e.g., TSC-capped 25 nm AuNPsphs) in similar physical conditions. Further, the theoretical calculation based on density functional theory (DFT) nicely corroborates with the experimental findings and discloses the effective contribution of grain-boundaries toward the free energy of hydrogen adsorption (ΔG H*) and the position of the d-band center, which play a crucial role in their HER activities.

Bimetallic Au–Ag hollow nanoprisms (HNPrs) with variable effective surface areas, dynamic atomic compositions (Au:Ag), and distinct stepped surfaces between the central porous region and crystalline periphery are synthesized through a modified seed-mediated growth followed by a sacrificial galvanic replacement method. Porous central-cavity-induced distortion from prism to disk shape generates an increased number of numerous low-coordinated crystal defects on the crystalline nanodisk surface along with extended d-orbital spacing of the respective crystal disorders in the central-cavity region of HNPrs to control their adsorption efficiency for different redox reactions. Among the different HNPrs, HNPr250 possesses the highest density of the grain boundary with a preferable Au0:Ag0 ratio to form an extensive porous ligamentous central cavity, acts as a superior electrocatalyst to accelerate the kinetics of the uric acid (UA) oxidation (8.4 times compared to the blank electrode), and allows us to detect UA even in the nanomolar range. Experimental observations have been supported by density functional theory calculation to approximate the effective Au–Au displacement with a suitable percentage of Ag in different HNPrs to explain their measured catalytic activity.

This review systematically outlines the underpinning mechanism and applications involved in electrochemically integrated carbon capture and utilization (CCU) processes together with techno-economic insights.

Spherical gold nanoseed (∼5–6 nm)-induced (but not seed-mediated) silver nanorods (Hy-Au@AgNRs) of variable lengths have been synthesized by a new methodology that shows enhancement in catalytic activity as a function of nanorod length. Detailed characterization by atomic-scale resolution spectroscopy, precision scattering measurements, high-resolution microscopy, and theoretical modeling through the density functional theory (DFT) quantifies the presence of an enhanced number of multiple coaxial twin boundaries for longer Hy-Au@AgNRs, which ultimately results in an increased mechanical strain. By considering greater mechanical strain within Hy-Au@AgNRs, the density of states (DOS) calculation shows a prominent shift in electron density toward the Fermi level to assist in the tremendous catalytic activity of the longest nanorod (NR) (Hy-Au@AgNR840). Further assembling of these inherently active Hy-Au@AgNR840s by thiol click chemistry not only efficiently creates multiple low-coordinated crystal sites to improve their catalytic activity but also the resultant uniform two-dimensional (2D) platform shows better adsorptivity and easy moldability on the electrode surface for increased shelf life, a uniform porous structure to trap a large extent of redox systems, enhanced stability in a broad pH and solvent range to increase the applicability, and long-term stability under ambient conditions for safe storing, making this material a unique nonenzymatic scalable universal electrocatalytic platform. The ability of this material to act as a nonenzymatic universal catalytic platform has been verified by applying it for highly specific and ultrasensitive detection of a series of human metabolites, which include different important vitamins, potent endogenous antioxidants, essential amino acids for the biosynthesis of proteins, simple monosaccharides, and essential trace-metal ions. Our study for the first time mechanistically explores the combined role of anisometric seeding to create an intermetallic twin boundary along with its size to control the strain-induced catalytic activity to offer us a universal 2D electrocatalytic sensing platform by a combined approach of experiment and theory.