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Tailoring the electrode structure and morphology with short diffusion distance for fast ions transport is of significant to improve rate capability for advanced lithium-ion batteries. A novel architecture of hollow Co3O4 nanocrystals in situ anchored on holey graphene is successfully fabricated, and individual hollow Co3O4 nanocrystal is located around one etched hole on graphene sheets. This newly fabricated nanostructure is able to greatly shorten mass diffusion distance for enhancement of Li ion transport, resulting in the best rate performance among previously reported composites of Co3O4 and graphene. This work reveals that high rate lithium-ion batteries can be achieved through constructing the hybrids of Co3O4 nanocrystals on in situ etched holey graphene, while rendering fundamental for enhancement of mass transport rate by highly shortened ions diffusion distance in a nanostructured electrode to accomplish superior rate capability.

Tuning the chemical composition and surface structure of electrodes is demonstrated as a feasible and effective strategy to tailor advanced catalysts for energy electrocatalysis. In this work, hierarchical palladium-silver alloy nanosheets (PdAg NS) with the thickness ~7 atoms and rich atomic defects are successfully prepared, using the carbon monoxide (CO) confinement approach. The optimized Pd7Ag3 NS/C exhibits 8.8 times higher catalytic peak current density and much better stability toward ethanol electrooxidation than Pd NS/C catalyst. The catalytic enhancement mechanism could be attributed to the synergetic effects among optimized electronic structure of Pd, novel architecture, and rich atomic defects.

The controllable preparation of noble metallic nanocrystals with a 3D architecture is of great interest for electrocatalysis applications due to their enhanced atomic utilization, facilitated mass transport, and other attractive properties. In this work, a facile, one-pot, and surfactant-free method of synthesizing heterophase sponge-like Pd (S-Pd) is developed. The prepared S-Pd has a four-fold higher peak current density and better durability than a commercial Pd/C catalyst for formic acid oxidation. It therefore has great potential as an anode catalyst for direct formic acid fuel cells.

Although PdRh-based bimetallic nanocrystals have been demonstrated as effective catalysts for methanol electrooxidation, the impact of introduced Rh on CO poisoning resistance and consequently the catalytic activity is still lacking in-depth studies. In this work, defective PdRh bimetallic nanocrystals (PdRh NAs) with different composition ratios are synthesized. The prepared Pd3Rh1 NAs exhibit much higher peak current density and greater durability in comparison with the control sample of Pd1Rh1 NAs, Pd5Rh1 NAs, and the Commercial Pd/C. In addition, we observe that the introduced suitable amount of Rh plays a critical role in promoting the activity and stability of PdRh NAs for methanol electrooxidation reaction (MOR). This work provides an advanced MOR catalyst, and highlights that modulating both surface structure and chemical composition of catalysts is an effective route to realize catalytic property optimization.

Noble metal-based nanosheets are demonstrated as promising electrodes for energy electrocatalysis due to their remarkable advantages such as large surface area to volume ratio and high utilization efficiency of noble metals. In this work, three-dimensional layered palladium tungsten nanosheet assemblies (L-PdW NAs) have been successfully synthesized using a facile carbon monoxide (CO) confinement strategy, exhibiting much higher catalytic activity and stability toward both ethanol oxidation reaction (EOR) and methanol oxidation reaction (MOR) compared to palladium nanosheets (Pd NSs) and commercial Pd/C (Com Pd/C). It is discovered that the tungsten hexacarbonyl (W(CO)6) in the synthetic system displays a decisive key in forming the layered nanosheet structure. The catalytic enhancement mechanism should result the synergetic effects between the introduced W and novel architecture of layered nanosheet assembles. This work offers a low Pd loading, highly active and stable anode catalyst for direct alcohol fuel cells, while highlighting the beauty of the architecture with introduced W to significantly enhance the catalytic activity.

Great efforts have been devoted to the exploration of PdCu-based catalysts toward formic acid oxidation, but their activity is still much lower than that expected. In this work, nanotwin-rich PdCuW trimetallic nanochains were successfully fabricated using a modified polyol method. The formation of crystalline defect of nanotwins should be related to the significant lattice mismatch among Pd, Cu, and the introduced W. It is discovered that the nanotwins could function as superb active sites to highly improve the peak current density of formic acid oxidation. In addition, the W- and Cu-tailored PdCuW nanochains optimize the electronic structure of Pd with suitable binding energy to reduce the charge-transfer resistance, resulting in greatly enhanced catalytic activity. This work highlights the beauty of the architecture with introduced W to significantly enhance catalytic performance in particular the activity of formic acid electrooxidation.

The modification of electronic structure can significantly affect electrocatalytic activity. An architecture art of Pt-skinned PtAg bimetallic nanotubes is successfully synthesized, delivering much higher catalytic activity and better stability toward methanol electrooxidation than PtAg bimetallic nanoparticles and commercial Pt/C catalysts. Theoretical studies reveal that the Pt skin on PtAg bimetallic nanotubes prominently optimize the electronic structure of Pt to greatly enhance the dissociative adsorption of methanol while increasing CO poisoning resistance for fast electrode kinetics, high catalytic current density and stability. This work offers a low Pt loading but highly active anode catalyst for direct methanol fuel cells, demonstrating that rationally tuning the electronic structure by well-controlling surface morphology in nanoscales could open new opportunities to greatly improve the electrocatalytic properties.

Hollow cobalt oxide nanoparticles embedded porous reduced graphene oxide hybrids are constructed by means of a facile etching strategy and the Kirkendall effect. When examined as an anode for lithium-ion batteries, this unique structured composite exhibits remarkable lithium storage capability such as excellent rate capability, superior reversible specific capacity together with good cycling durability, highlighting the importance of embedding active materials on graphene sheets for maximum utilization of hollow structured cobalt oxide and porous reduced graphene oxide for energy devices.

Perforated ultrathin Pd nanosheets with crystalline/amorphous heterostructures are rationally synthesized to offer a large electrochemically active surface area of 172.6 m2 g-1 and deliver a 5.6 times higher apparent reaction rate in comparison to commercial Pd/C, thus offering a facile confined growth method to generate superior catalysts.