Efficient water electrolysis for hydrogen production constitutes a key segment for the upcoming hydrogen economy, but has been impeded by the lack of high-performance and low-cost electrocatalysts for, ideally, simultaneously expediting the kinetics of both hydrogen and oxygen evolution reactions (HER and OER). In this study, the favored binding energetics of OER and HER reaction intermediates on iron-doped nickel phosphides are first predicted by density functional theory (DFT) simulations, and then experimentally verified through the fabrication of Fe-doped Ni2P nanoparticles embedded in carbon nanotubes using metal–organic framework (MOF) arrays on nickel foam as the structural template. Systematic investigations on the effect of phosphorization and Fe doping reveal that while the former endows a larger benefit on OER than on HER, the latter enables not only modulating the electronic structure, but also tuning the micromorphology of the catalyst, synergistically leading to both enhanced HER and OER. As a result, extraordinary performances of constant water electrolysis are demonstrated requiring only a cell voltage of 1.66 V to afford a current density of 500 mA cm–2, far outperforming the benchmark electrode couple composed of Pt/C and RuO2. Postelectrolysis characterizations combined with DFT inspection further reveal that while the Fe-doped Ni2P species are mostly retained after prolonged HER, they are in situ converted to Fe/P-doped γ-NiOOH during OER, serving as the actual OER active sites with high activity.

The development of redox-targeting co-catalysts is one of the important tasks in realizing hybrid photocatalytic systems for CO2 reduction reaction (CO2 RR), which has been sought after as a promising way to mitigate the energy and environmental crisis. In this study, hollow nickel hydroxide nanocages are successfully fabricated via an ion-assisted etching protocol using ZIF-8 as the structural template, and they are used as cocatalysts along with a molecular photosensitizer and sacrificial electron donor for reducing visible-light CO2. A remarkable CO evolution rate of 1.44 × 105 μmol·g ‑1 co‑cat·h–1, a CO selectivity of 96.1%, and a quantum efficiency of 2.50% are achieved using the optimal cavernous structure with thin walls, attributing to the significantly improved light harvest owing to multiple light reflection and scattering, static electron transfer, abundant surface oxygen vacancies, as well as coherent energy flow among well-aligned band levels. This study highlights the design and development of hollow entities toward CO2 RR and provides insights into the structure-mediated photocatalytic response.

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A novel potentially tridentate N-heterocyclic carbene (NHC) precursor, anionic salicylaldimine-functionalized imidazolium bromide, [3,5-t Bu 2 -2-(HO)C 6 H 2 CHdNCH 2 CH 2 (CH-{NCHCHN i Pr})Br] (HL‚HBr, 2), was designed. The reaction of in situ-generated monoanionic tridentate salicylaldiminato-functionalized NHC LNa with Ni(PPh 3 ) 2 Br 2 affords a novel monoligand Ni(II) bromide, [3,5-t Bu 2 -2-(O)C 6 H 2 CHdNCH 2 CH 2 (C{NCHCHN i Pr})]NiBr (LNiBr , 3), in good yield. Complex 3 can also be synthesized by the direct reaction of nickelocene (Cp) 2 Ni or bis-indenyl Ni(II) complex (Ind) 2 Ni with 2 in high yield via the cyclopentadiene or indene elimination reaction, respectively. Complex 3 has been fully characterized including X-ray structural determination. Preliminary study indicated that 3 shows good catalytic activity for the polymerization of styrene in the presence of NaBPh 4 at 80 °C.

Despite the widespread use of quantum dots (QDs) for biosensing and bioimaging, QD-based bio-interfaceable and reconfigurable molecular computing systems have not yet been realized. DNA-programmed dynamic assembly of multi-color QDs is presented for the construction of a new class of fluorescence resonance energy transfer (FRET)-based QD computing systems. A complete set of seven elementary logic gates (OR, AND, NOR, NAND, INH, XOR, XNOR) are realized using a series of binary and ternary QD complexes operated by strand displacement reactions. The integration of different logic gates into a half-adder circuit for molecular computation is also demonstrated. This strategy is quite versatile and straightforward for logical operations and would pave the way for QD-biocomputing-based intelligent molecular diagnostics.