Single Crystals of α-MoO-Intercalated {Ni(HO)} and Electrocatalytic Water Reduction: Toward a Class of Molybdenum Bronzes.

We have successfully intercalated {Ni(HO)} into the α-MoO layer, leading to the isolation of green single crystals of [MoO(CHCOO){Ni(HO)}]·HO (). The homogeneous electrochemistry of in its aqueous solution exhibits electrocatalytic hydrogen evolution reaction (HER) with concomitant electrochemical deposition of [HMoMoO(CHCOO){Ni(HO)(OH)}] (). Compound , a new molybdenum bronze, acts as an efficient and stable heterogeneous electrocatalyst for water reduction to molecular hydrogen.

Nanoblackberries of {WFe} and {MoFe}: Electrocatalytic Water Reduction.

The self-assembly of a {MoFe} cluster into nanoblackberries in a dilute solution of the relevant crystalline compound [MoFeO(CHCOO){MoO(HO)}{HMoO(HO)}(HO)]·150HO () was demonstrated by Liu, Müller, and their co-workers as a landmark discovery in the area of polyoxometalate chemistry. We have described, in the present work, how these ∼2.5 nm nano-objects, (M = W, Mo) can be self-assembled into nanoblackberries , leading to their solid-state isolation as the nanomaterials Fe[WFeO(CHCOO)(OH)(HO)]·180HO () and Na[MoFeO(CHCOO)(OH)(HO)]·180HO (), respectively (NM stands for nanomaterial).

Efficient homogeneous electrocatalytic hydrogen evolution using a Ni-containing polyoxometalate catalyst.

NiCl·6HO ([Ni(HO)]Cl) does not show electrocatalytic hydrogen evolution reaction activity (HER) in an acidic aqueous medium as well as in neutral water. Interestingly, when [Ni(HO)] is present in a polyoxovanadate matrix, for example, in the compound K[Ni(HO)][VO]·4HO (1), it exhibits homogeneous electrocatalytic HER activity in an acidic aqueous solution with a turn over frequency of 2.1 s and an effective low overpotential of 127 mV at pH 2.

Deciphering the Ultrafast Nonlinear Optical Properties and Dynamics of Pristine and Ni-Doped CsPbBr Colloidal Two-Dimensional Nanocrystals.

While the unabated race persists in achieving record efficiencies in solar cells and other photonic/optoelectronic devices using lead halide perovskite absorbers, a comprehensive picture of the correlated third-order nonlinear optical (NLO) properties is yet to be established. The present study is aimed at deciphering the role of dopants in multiphoton absorption properties of intentionally engineered CsPbBr colloidal nanocrystals (NCs). The charge separation of the plasmon-semiconductor conduction band owing to the hot electron transfer at the interface was demystified using the dynamics of the bleached spectral data from femtosecond (fs) transient absorption spectroscopy with broadband capabilities.