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Electrochemical carbon dioxide (CO 2 ) reduction can in principle convert carbon emissions to fuels and value-added chemicals, such as hydrocarbons and alcohols, using renewable energy, but the efficiency of the process is limited by its sluggish kinetics 1 , 2 . Molecular catalysts have well defined active sites and accurately tailorable structures that allow mechanism-based performance optimization, and transition-metal complexes have been extensively explored in this regard. However, these catalysts generally lack the ability to promote CO 2 reduction beyond the two-electron process to generate more valuable products 1 , 3 . Here we show that when immobilized on carbon nanotubes, cobalt phthalocyanine—used previously to reduce CO 2 to primarily CO—catalyses the six-electron reduction of CO 2 to methanol with appreciable activity and selectivity. We find that the conversion, which proceeds via a distinct domino process with CO as an intermediate, generates methanol with a Faradaic efficiency higher than 40 per cent and a partial current density greater than 10 milliamperes per square centimetre at −0.94 volts with respect to the reversible hydrogen electrode in a near-neutral electrolyte. The catalytic activity decreases over time owing to the detrimental reduction of the phthalocyanine ligand, which can be suppressed by appending electron-donating amino substituents to the phthalocyanine ring. The improved molecule-based electrocatalyst converts CO 2 to methanol with considerable activity and selectivity and with stable performance over at least 12 hours. Individual cobalt phthalocyanine derivative molecules immobilized on carbon nanotubes effectively catalyse the electroreduction of CO 2 to methanol via a domino process with high activity and selectivity and stable performance.

Metal phthalocyanines (MePcs) have been considered as promising catalysts for CO 2 reduction electrocatalysis due to high turnover frequency and structural tunability. However, their performance is often limited by low current density and the performance of some systems is controversial. Here, we report a carbon nanotube (CNT) hybridization approach to study the electrocatalytic performance of MePcs (Me = Co, Fe and Mn). MePc molecules are anchored on CNTs to form the hybrid materials without noticeable molecular aggregations. The MePc/CNT hybrids show higher activities and better stabilities than their molecular counterparts. FePc/CNT is slightly less active than CoPc/CNT, but it could deliver higher Faradaic efficiencies for CO production at low overpotentials. In contrast, the catalytic performance of MePc molecules directly loaded on substrate is hindered by molecular aggregation, especially for FePc and MnPc. Our results suggest that carbon nanotube hybridization is an efficient approach to construct advanced MePc electrocatalysts and to understand their catalytic performance.

Molybdenum disulfide (MoS2)‐based materials have been recently identified as promising electrocatalysts for hydrogen evolution reaction (HER). However, little work has been done to improve the catalytic performance of MoS2 toward HER in alkaline electrolytes, which is more suitable for water splitting in large‐scale applications. Here, it is reported that the hybridization of 0D nickel hydr(oxy)oxide nanoparticles with 2D metallic MoS2 nanosheets can significantly enhance the HER activities in alkaline and neutral electrolytes. Impressively, the optimized hybrid catalyst can drive a cathodic current density of 10 mA cm−2 at an overpotential of ≈73 mV for HER in 1 m KOH, about 185 mV smaller than the original MoS2. The improved HER activity is attributed to a bifunctional mechanism adopted in these hybrid catalysts, in which nickel hydr(oxy)oxide promotes the water adsorption and dissociation to supply protons for subsequent reactions occurred on MoS2 to generate H2. 1T‐MoS2 nanosheets hybridized with nickel hydr(oxy)oxide nanoparticles can synergistically facilitate the hydrogen evolution reaction (HER) in alkaline and neutral electrolytes through a bifunctional mechanism. The optimized hybrid catalyst can drive a cathodic current density of 10 mA cm−2 at an overpotential of ≈73 mV for HER in 1 m KOH, about 185 mV smaller than the original MoS2.

Catalysts for oxygen reduction and evolution reactions are at the heart of key renewable-energy technologies including fuel cells and water splitting. Despite tremendous efforts, developing oxygen electrode catalysts with high activity at low cost remains a great challenge. Here, we report a hybrid material consisting of Co 3 O 4 nanocrystals grown on reduced graphene oxide as a high-performance bi-functional catalyst for the oxygen reduction reaction (ORR) and oxygen evolution reaction (OER). Although Co 3 O 4 or graphene oxide alone has little catalytic activity, their hybrid exhibits an unexpected, surprisingly high ORR activity that is further enhanced by nitrogen doping of graphene. The Co 3 O 4 /N-doped graphene hybrid exhibits similar catalytic activity but superior stability to Pt in alkaline solutions. The same hybrid is also highly active for OER, making it a high-performance non-precious metal-based bi-catalyst for both ORR and OER. The unusual catalytic activity arises from synergetic chemical coupling effects between Co 3 O 4 and graphene. Developing oxygen-electrode catalysts with high activity at low cost for renewable energy applications such as water splitting and fuel cells is challenging. A hybrid material of Co 3 O 4 nanocrystals grown on reduced graphene oxide exhibits enhanced catalytic performance for the oxygen reduction and oxygen evolution reactions.

Non-invasive deep-tissue three-dimensional optical imaging of live mammals with high spatiotemporal resolution is challenging owing to light scattering. We developed near-infrared II (1,000–1,700 nm) light-sheet microscopy with excitation and emission of up to approximately 1,320 nm and 1,700 nm, respectively, for optical sectioning at a penetration depth of approximately 750 μm through live tissues without invasive surgery and at a depth of approximately 2 mm in glycerol-cleared brain tissues. Near-infrared II light-sheet microscopy in normal and oblique configurations enabled in vivo imaging of live mice through intact tissue, revealing abnormal blood flow and T-cell motion in tumor microcirculation and mapping out programmed-death ligand 1 and programmed cell death protein 1 in tumors with cellular resolution. Three-dimensional imaging through the intact mouse head resolved vascular channels between the skull and brain cortex, and allowed monitoring of recruitment of macrophages and microglia to the traumatic brain injury site.Light-sheet microscopy in the NIR-II window enables rapid volumetric imaging of tissues at impressive depths in vivo without invasive preparations owing to the reduced light scattering and tissue autofluorescence at these wavelengths.

Electrochemical reduction of CO 2 is a promising route for sustainable production of fuels. A grand challenge is developing low-cost and efficient electrocatalysts that can enable rapid conversion with high product selectivity. Here we design a series of nickel phthalocyanine molecules supported on carbon nanotubes as molecularly dispersed electrocatalysts (MDEs), achieving CO 2 reduction performances that are superior to aggregated molecular catalysts in terms of stability, activity and selectivity. The optimized MDE with methoxy group functionalization solves the stability issue of the original nickel phthalocyanine catalyst and catalyses the conversion of CO 2 to CO with >99.5% selectivity at high current densities of up to −300 mA cm −2 in a gas diffusion electrode device with stable operation at −150 mA cm −2 for 40 h. The well-defined active sites of MDEs also facilitate the in-depth mechanistic understandings from in situ/operando X-ray absorption spectroscopy and theoretical calculations on structural factors that affect electrocatalytic performance. Widespread deployment of electrochemical CO 2 reduction requires low-cost catalysts that perform well at high current densities. Zhang et al. show that methoxy-functionalized nickel phthalocyanine molecules on carbon nanotubes can operate as high-performing molecularly dispersed electrocatalysts at current densities of up to −300 mA cm –2 .

Promoting the intrinsic activity and accessibility of basal plane sites in 2D layered metal dichalcogenides is desirable to optimize their catalytic performance for energy conversion and storage. Herein, a core/shell structured hybrid catalyst, which features few‐layered ruthenium (Ru)‐doped molybdenum disulfide (MoS2) nanosheets closely sheathing around multiwalled carbon nanotube (CNT), for highly efficient hydrogen evolution reaction (HER) is reported. With 5 at% (atomic percent) Ru substituting for Mo in MoS2, Ru‐MoS2/CNT achieves the optimum HER activity, which displays a small overpotential of 50 mV at −10 mA cm−2 and a low Tafel slope of 62 mV dec−1 in 1 m KOH. Theoretical simulations reveal that Ru substituting for Mo in coordination with six S atoms is thermodynamically stable, and the in‐plane S atoms neighboring Ru dopants represent new active centers for facilitating water adsorption, dissociation, and hydrogen adsorption/desorption. This work provides a multiscale structural and electronic engineering strategy for synergistically enhancing the HER activity of transition metal dichalcogenides. A core/shell structured hybrid of ruthenium (Ru)‐doped molybdenum disulfide (MoS2) and carbon nanotube is constructed as a high‐performance electrocatalyst for the hydrogen evolution reaction. Experimental and theoretical studies demonstrate that Ru substituting for Mo in MoS2 could efficiently activate the neighboring S atoms in the basal plane, and thus give rise to outstanding hydrogen evolution reaction catalytic activity.

Electrochemical reduction of carbon dioxide with renewable energy is a sustainable way of producing carbon-neutral fuels. However, developing active, selective and stable electrocatalysts is challenging and entails material structure design and tailoring across a range of length scales. Here we report a cobalt-phthalocyanine-based high-performance carbon dioxide reduction electrocatalyst material developed with a combined nanoscale and molecular approach. On the nanoscale, cobalt phthalocyanine (CoPc) molecules are uniformly anchored on carbon nanotubes to afford substantially increased current density, improved selectivity for carbon monoxide, and enhanced durability. On the molecular level, the catalytic performance is further enhanced by introducing cyano groups to the CoPc molecule. The resulting hybrid catalyst exhibits >95% Faradaic efficiency for carbon monoxide production in a wide potential range and extraordinary catalytic activity with a current density of 15.0 mA cm −2 and a turnover frequency of 4.1 s −1 at the overpotential of 0.52 V in a near-neutral aqueous solution. Electrochemical reduction of carbon dioxide is a sustainable way of producing carbon-neutral fuels. Here, the authors take a combined nanoscale and molecular approach to develop a highly active and selective cobalt phthalocyanine/carbon nanotube hybrid electrocatalyst for carbon dioxide reduction to carbon monoxide.

Primary and rechargeable Zn-air batteries could be ideal energy storage devices with high energy and power density, high safety and economic viability. Active and durable electrocatalysts on the cathode side are required to catalyse oxygen reduction reaction during discharge and oxygen evolution reaction during charge for rechargeable batteries. Here we developed advanced primary and rechargeable Zn-air batteries with novel CoO/carbon nanotube hybrid oxygen reduction catalyst and Ni-Fe-layered double hydroxide oxygen evolution catalyst for the cathode. These catalysts exhibited higher catalytic activity and durability in concentrated alkaline electrolytes than precious metal Pt and Ir catalysts. The resulting primary Zn-air battery showed high discharge peak power density ~265 mW cm −2 , current density ~200 mA cm −2 at 1 V and energy density >700 Wh kg −1 . Rechargeable Zn-air batteries in a tri-electrode configuration exhibited an unprecedented small charge–discharge voltage polarization of ~0.70 V at 20 mA cm −2 , high reversibility and stability over long charge and discharge cycles. Metal-air batteries are promising for energy storage because of their high theoretical energy density, but their realization is hampered by the lack of efficient and robust air catalysts. Li et al . construct stable zinc-air batteries using novel catalysts for oxygen reduction and evolution reactions.

Restructuring-induced catalytic activity is an intriguing phenomenon of fundamental importance to rational design of high-performance catalyst materials. We study three copper-complex materials for electrocatalytic carbon dioxide reduction. Among them, the copper(II) phthalocyanine exhibits by far the highest activity for yielding methane with a Faradaic efficiency of 66% and a partial current density of 13 mA cm −2 at the potential of – 1.06 V versus the reversible hydrogen electrode. Utilizing in-situ and operando X-ray absorption spectroscopy, we find that under the working conditions copper(II) phthalocyanine undergoes reversible structural and oxidation state changes to form ~ 2 nm metallic copper clusters, which catalyzes the carbon dioxide-to-methane conversion. Density functional calculations rationalize the restructuring behavior and attribute the reversibility to the strong divalent metal ion–ligand coordination in the copper(II) phthalocyanine molecular structure and the small size of the generated copper clusters under the reaction conditions. The catalytic conversion of carbon dioxide into value-added products requires an understanding of the active species present under working conditions. Here, the authors discover copper-containing complexes to reversibly transform during electrocatalysis into methane-producing copper nanoclusters.