MXenes are promising cathode materials for aqueous zinc-ion batteries (AZIBs) owing to their layered structure, metallic conductivity, and hydrophilicity. However, they suffer from low capacities unless they are subjected to electrochemically induced second phase formation, which is tedious, time-consuming, and uncontrollable. Here we propose a facile one-step surface selenization strategy for realizing advanced MXene-based nanohybrids. Through the selenization process, the surface metal atoms of MXenes are converted to transition metal selenides (TMSes) exhibiting high capacity and excellent structural stability, whereas the inner layers of MXenes are purposely retained. This strategy is applicable to various MXenes, as demonstrated by the successful construction of VSe2@V2CT x , TiSe2@Ti3C2T x , and NbSe2@Nb2CT x . Typically, VSe2@V2CT x delivers high-rate capability (132.7 mA h g–1 at 2.0 A g–1), long-term cyclability (93.1% capacity retention after 600 cycles at 2.0 A g–1), and high capacitive contribution (85.7% at 2.0 mV s–1). Detailed experimental and simulation results reveal that the superior Zn-ion storage is attributed to the engaging integration of V2CT x and VSe2, which not only significantly improves the Zn-ion diffusion coefficient from 4.3 × 10–15 to 3.7 × 10–13 cm2 s–1 but also provides sufficient structural stability for long-term cycling. This study offers a facile approach for the development of high-performance MXene-based materials for advanced aqueous metal-ion batteries.

Triply periodic constant mean curvature surface structures have been discovered in a variety of biological and self-assembly systems. Among them, the single gyroid is of significant interest, because of its unique geometry, inherent chirality, and corresponding spectacular optical properties. Despite theoretical and experimental efforts on this structure, so far, limited progress has been made regarding the formation of the single-network structures and the structural relationships with the thermodynamically stable double networks. Herein, we report the electron microscopic observation and analysis on the interconversion between the single gyroid and double diamond structure in an amphiphilic ABC triblock terpolymer templated macroporous silica synthesis system with a solvent mixture of tetrahydrofuran and water. The two structures were interconnected by a “side-by-side” epitaxial relationship with rescaling of the unit cell. The single-network structure was formed via a new type of alternating gyroid under the restricted epitaxial intergrowth, in which the hydrophilic block with the silica source and the solvent tetrahydrofuran formed the two chemically distinct, interpenetrating gyroid networks of opposite chirality in a matrix of the hydrophobic block.

12,13. This allows for an unprecedented control of cluster steering relevant for nanomanipulations on surfaces. An important step towards the bottom-up assembly of nanoscopic functional components from atomic building blocks is the controlled translation and positioning of atoms and molecular clusters on surfaces by external forces 14. At macroscopic scales, objects typically follow the direction of an external force. This is no longer true for microscopic components on atomically corrugated substrates, where particle trajectories can lock to substrate lattice directions since they provide low-energy corridors within the potential-energy landscape. Such directional locking has been previously observed for nanocrystals migrating over atomic surfaces 1,2 and microparticles on arrays of obstacles 3-5 or optical traps 6,7 but also in flux flow of type-II superconductors 8. In addition to their fundamental understanding, deviations between the direction of particle motion and the applied force have important consequences for the manipulation of atoms on surfaces and must therefore be considered in bottom-up assembly strategies. Contrasting with isolated or weakly interacting particles 8-11 , however, little is known about the driven motion of spatially extended crystalline clusters across periodic surfaces 15. Here we experimentally and numerically study the translational and the orientational motion of micrometresized colloidal clusters with up to N = 400 particles that are driven across a patterned surface. Although the governing forces and their range are very different in colloidal systems, tribological experiments suggest a close resemblance with observations in atomic systems 16. Such system-independent features are in perfect agreement with the Frenkel-Kontorova model 17 that ignores all details regarding the relevant forces and considers just a monolayer of interacting particles on a corrugated surface. Compared to atomic clusters, where well-defined driving forces are difficult to realize by means of

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The macroporous silica synthesis system with the ABC triblock terpolymer poly(ethylene oxide)-block-polystyrene-block-poly(tert-butyl acrylate) (denoted as OSA) as template and tetraethyl orthosilicate as silica source under acidic conditions in a mixture solvent of tetrahydrofuran and H 2 O has been investigated, and two synthesis−field phase diagrams are plotted. Eight different structures varied from normal-phase (oil in water) cage-type (n-C), normal-phase 2D hexagonal (n-H), and lamellar (L) to unique inverse-phase (water in oil) hyperbolic-surface (i-HS) structures, including the shifted double-diamond (i-SDD), single-gyroid (i-SG), and shifted double-primitive (i-SDP), inverse-phase 2D hexagonal (i-H) and inverse-phase micellar (i-M) structures, have been formed by varying the degree of polymerization of the hydrophobic blocks in OSA. From the two-component phase diagram, it can be concluded that the macroporous structures formation is affected by the packing parameter p and the segregation product (χN) of the hydrophilic and hydrophobic blocks. With an increase in p, the structures n-C and n-H were found in the range of low χN, whereas the structures i-HS, i-H, and i-M were found in the range of higher χN, while L is in between. In the threecomponent phase diagram, different volume fraction ratios (VFR) of the hydrophobic/hydrophilic block (S/O, A/O) and those of hydrophobic/hydrophobic block (S/A) in this co-assembly system divided the resultant ordered structures in various regions. The n-C, n-H, and L structures were found in low VFRs of S/O and A/O; i-H and i-M structures were formed in high VFRs of S/O and A/O. The formations of the i-HS structures including i-SDD, i-SDP, and i-SG are depending on low VFRs regions of S/ O and S/A with similar packing parameter.