Bridging polymer design with catalyst surface science is a promising direction for tuning and optimizing electrochemical reactors that could impact long-term goals in energy and sustainability. Particularly, the interaction between inorganic catalyst surfaces and organic-based ionomers provides an avenue to both steer reaction selectivity and promote activity. Here, we studied the role of imidazolium-based ionomers for electrocatalytic CO 2 reduction to CO (CO 2 R) on Ag surfaces and found that they produce no effect on CO 2 R activity yet strongly promote the competing hydrogen evolution reaction (HER). By examining the dependence of HER and CO 2 R rates on concentrations of CO 2 and HCO 3 − , we developed a kinetic model that attributes HER promotion to intrinsic promotion of HCO 3 − reduction by imidazolium ionomers. We also show that varying the ionomer structure by changing substituents on the imidazolium ring modulates the HER promotion. This ionomerstructure dependence was analyzed via Taft steric parameters and density functional theory calculations, which suggest that steric bulk from functionalities on the imidazolium ring reduces access of the ionomer to both HCO 3 − and the Ag surface, thus limiting the promotional effect. Our results help develop design rules for ionomer−catalyst interactions in CO 2 R and motivate further work into precisely uncovering the interplay between primary and secondary coordination in determining electrocatalytic behavior.

The development of new resist materials is vital to fabrication techniques for next-generation microelectronics. Inorganic resists are promising candidates because they have higher etch resistance, are more impervious to pattern collapse, and are more absorbing of extreme ultraviolet (EUV) radiation than organic resists. However, there is limited understanding about how they behave under irradiation. In this work, a Hf-based hybrid thin film resist, known as “hafnicone”, is deposited from the vapor-phase via molecular layer deposition (MLD), and its electron-beam and deep-ultraviolet (DUV)-induced patterning mechanism is explored. The hafnicone thin films are deposited at 100 °C by using the Hf precursor tetrakis­(dimethyl­amido)­hafnium­(IV) and the organic precursor ethylene glycol. E-beam lithography, scanning electron microscopy, and profilometry are used to investigate the resist performance of hafnicone. With 3 M HCl as the developer, hafnicone behaves as a negative tone resist which exhibits a sensitivity of 400 μC/cm2 and the ability to resolve 50 nm line widths. The resist is characterized via X-ray photoelectron spectroscopy (XPS) and infrared spectroscopy (IR) to investigate the patterning mechanism, which is described in the context of classical nucleation theory. This study of hafnicone hybrid MLD demonstrates the ability for the bottom-up vapor deposition of inorganic resists to be utilized in advanced e-beam and DUV lithographic techniques.

As one of the most attractive transition metal dichalcogenides (TMDs), the growth of molybdenum disulfide (MoS2) with industrial compatibility is of great importance. Atomic layer deposition (ALD) has been shown to be a promising method to achieve the growth of high-quality TMD materials. However, MoS2 films deposited by ALD often are amorphous with nonideal stoichiometry and require high-temperature post-deposition annealing. In this study, we introduce a modified ALD recipe using Mo(CO)6 and H2S, resulting in controllable linear growth behavior, a S-to-Mo ratio of 2:1, and crystalline films at a temperature as low as 190 °C. The growth mechanisms and key factors leading to this improvement are proposed and complemented by kinetics calculations. This newly developed methodology relies on aligning the process time with the reaction kinetics of carbonyl disassociation. The MoS2 films prepared herein were shown to be active hydrogen evolution reaction catalysts.

Molecular layer deposition (MLD) is an attractive, vapor-phase deposition method for applications requiring ultrathin organic materials, such as photolithography, lithium batteries, and microelectronics. By using sequential self-limiting surface reactions, MLD offers excellent control over thickness and conformality, but there are also challenges such as a limited range of possible film compositions and long deposition times. In this study, we introduce a modified technique, termed ionic liquid assisted MLD (IL-MLD), that can overcome these barriers. By performing the surface reactions inside of an ultrathin layer of a compatible ionic liquid (IL), solvent effects are replicated inside a vacuum system, broadening the possible reactions to a much wider suite of chemistries. Using this strategy, the MLD of polyetherketoneketone, an industrially and research-relevant, high-performance thermoplastic, is reported. With this proof-of-concept, we demonstrate that IL-MLD can enable the synthesis of polymers via solvent-or catalyst-mediated reactions and establish an approach that may allow solution chemistries to be accessed in other vapor deposition techniques as well.

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