Nanocage-chain fuel cell catalysts: The expense and scarcity of platinum has driven efforts to improve oxygen-reduction catalysts in proton-exchange membrane fuel cells. Tian et al. synthesized chains of platinum-nickel alloy nanospheres connected by necking regions. These structures can be etched to form nanocages with platinum-rich surfaces that are highly active for oxygen reduction. In fuel cells running on air and hydrogen, these catalysts operated for at least 180 hours. Science , this issue p. 850

Nickel–iron composites are efficient in catalyzing oxygen evolution. Here, we develop a microorganism corrosion approach to construct nickel–iron hydroxides. The anaerobic sulfate-reducing bacteria, using sulfate as the electron acceptor, play a significant role in the formation of iron sulfide decorated nickel–iron hydroxides, which exhibit excellent electrocatalytic performance for oxygen evolution. Experimental and theoretical investigations suggest that the synergistic effect between oxyhydroxides and sulfide species accounts for the high activity. This microorganism corrosion strategy not only provides efficient candidate electrocatalysts but also bridges traditional corrosion engineering and emerging electrochemical energy technologies.

A highly luminescent LnMOF {[Eu₂(bqdc)₃(H₂O)(DMF)₃]·0.5DMF·H₂O}_n (1, bqdc = 2,2′-biquinoline-4,4′-dicarboxylate) was designed and synthesized. It was characterized by single crystal X-ray diffraction, PXRD, TGA, EA and FT-IR. A new strategy for preparing mechanically robust MOF thin films was developed by electrodeposition in combination with subsequent solvothermal synthesis. A portable sensor device prototype consisting of a film of 1 was conveniently fabricated by using this new strategy and this sensor device exhibits a highly selective response to Hg²⁺. Its luminescence quenching can be distinguished clearly with the naked eye when illuminated by a handy UV banknote detector. The diffusion kinetics of Hg²⁺ into the LnMOF film is first proposed.

Two molecules, 1-hydroxypyrene-2-carbaldehyde (HP) and 1-methoxypyrene-2-carbaldehyde (MP) were explored. We investigated their photophysical properties, using experimental transient absorption and theoretical density functional theory/time-dependent density functional theory (DFT/TDDFT). HP and MP have similar geometric conformations but exhibit entirely different photophysical properties upon excitation into the S₁ state. In contrast to traditional excited state intramolecular proton transfer (ESIPT) in molecules that exhibit either single or dual fluorescence, HP has an unusual non-fluorescent property. Specifically, the ultrafast ESIPT process occurs in 158 fs and is followed by an intersystem crossing (ISC) component of 11.38 ps. In contrast to HP, MP undergoes only an 8 ps timescale process, which was attributed to interactions between solute and solvent. We concluded that this difference arises from intramolecular hydrogen bonds (IMHBs), which induce drastic structural alterntion upon excitation.