Surface-enhanced Raman spectroscopy (SERS) has developed into one of the most important tools in analytical and surface sciences since its discovery in the mid-1970s. Recent work on the SERS of transition metals concluded that transition metals, other than Cu, Ag, and Au, can also generate surface enhancement as high as 4 orders of magnitude. The present article gives an overview of recent progresses in the field of Raman spectroscopy on transition metals, including experimental, theory, and applications. Experimental considerations of how to optimize the experimental conditions and calculate the surface enhancement factor are discussed first, followed by a very brief introduction of preparation of SERS-active transition metal substrates, including massive transition metal surfaces, aluminum-supported transition metal electrodes, and pure transition metal nanoparticle assembled electrodes. The advantages of using SERS in investigating surface bonding and reaction are illustrated for the adsorption and reaction of benzene on Pt and Rh electrodes. The electromagnetic enhancement, mainly lightning-rod effect, plays an essential role in the SERS of transition metals, and that the charge-transfer effect is also operative in some specific metal-molecule systems. An outlook for the field of Raman spectroscopy of transition metals is given in the last section, including the preparation of well-ordered or well-defined nanostructures, and core-shell nanoparticles for investigating species with extremely weak SERS signals, as well as some new emerging techniques, including tip-enhanced Raman spectroscopy and an in situ measuring technique.

Resolving atomic site-specific electronic properties and correlated substrate-molecule interactions is challenging in real space. Now, mapping of sub-10 nm sized Pt nanoislands on a Au(111) surface was achieved by tip-enhanced Raman spectroscopy, using the distinct Raman fingerprints of adsorbed 4-chlorophenyl isocyanide molecules. A spatial resolution better than 2.5 nm allows the electronic properties of the terrace, step edge, kink, and corner sites with varying coordination environments to be resolved in real space in one Pt nanoisland. Calculations suggest that low-coordinate atomic sites have a higher d-band electronic profile and thus stronger metal-molecule interactions, leading to the observed blue-shift of Raman frequency of the N≡C bond of adsorbed molecules. An experimental and theoretical study on Pt(111) and mono- and bi-atomic layer Pt nanoislands on a Au(111) surface reveals the bimetallic effect that weakens with the increasing number of deposited Pt adlayer.

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Lithium metal has shown great promise as an anode material for high‐energy rechargeable batteries. However, interfacial instability caused by an unstable solid‐electrolyte interphase (SEI) and dendrite growth has impeded the realization of Li anodes for practical applications. Recently, we reported a potentiostatic stripping−galvanostatic plating electrochemical polishing method to simultaneously create atomically flat Li and a molecularly smooth SEI, leading to a near‐perfect Li anodes that exhibit much enhanced electrochemical performance. In this paper, key factors including anodic stripping potentials, cathodic plating current densities, and types of salt and solvent systems are further investigated in detail based on the understanding of electrode reactions taking place during polishing. In particular, the importance of considerations on the mutual constrains between electropolishing and SEI formation and, thus, the necessity of fine control of potential and/or current is elucidated, which serves as a general rule for the successful application of electrochemical polishing of Li as well as other metals that involve the formation of SEIs.

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