Template-assisted Strategy Research Articles

Template-assisted Flexible-to-rigid Transition of Peptides in Head-to-tail Self-polymerization Enables Sequence-controllable and Post-modifiable Peptide Nanofibers.

Peptide-based nanofibers are promising materials for many essential applications and can be generalized into two categories, self-assembling peptide nanofibers (SAPNs) and poly(amino acid) nanofibers (PAANs). Non-covalent SAPNs are sequence-controllable, but poorly stable and not suitable for post-modification. While covalent PAANs are post-modifiable, however, their sequences are either monotonic or undefined. The nanofibers obtained by head-to-tail covalent coupling polymerization of sequence-known peptides, which we call series-connected peptide nanofibers (SCPNs), promise to have the advantages of both SAPNs and PAANs, but they are barely reported. The undesired backbiting effect during the head-to-tail polymerization is one of the possible challenges. Here, we present a template-assisted strategy to trigger the flexible-to-rigid transition of peptide units, which can avoid the backbiting effect and enable consecutive intermolecular polymerization of peptides to produce desired sequence-controlled covalent SCPNs. SCPNs are highly stable and can function as excellent parent materials for various post-processing to create diverse hierarchical materials independent of the peptide sequence. Moreover, SCPNs allow for the display of predetermined functional groups at regular intervals along the nanofibers by pre-modification of the initial peptide sequence. SCPNs represent a new category of peptide-based nanofibers with outstanding performances and vast potential.

Low cost Non freeze-drying construction strategy of cellulose aerogels for efficient solar desalination

Aerogel-like materials with three-dimensional pore structures show great potential in the field of efficient solar-driven interfacial evaporation by virtue of their fast water transport as well as efficient energy confinement properties. However, the preparation of aerogels is currently limited by high-cost strategies such as freeze drying or supercritical drying. Here, we present a foam template-assisted (FTA) strategy for atmospheric pressure drying of cellulose nanofiber (CNF) aerogels. Building a robust CNF network is the key to resisting surface tension during water evaporation and achieving drying in ambient environments, which is achieved through cleverly designed ionic cross-linking with the help of FTA. Cellulose aerogel (CA) constructed using the FTA strategy exhibit lightweight (9 mg cm−3) and porous properties (porosity: > 99 %). The tannic-coated CA (TCA) was achieved by further polymerizing tannic acid on the CA surface, which has excellent photothermal conversion capability. Meanwhile, TCA achieved an impressive evaporation rate of 3.58 kg m-2h−1 and an energy efficiency of 97.2 % at 1sun radiation by virtue of its excellent energy confinement and water management capabilities. This strategy provides a promising solution for the low-cost construction of aerogels as well as for the realization of efficient solar-driven interfacial evaporators.

Solution-Processable MOF-on-MOF System Constructed via Template-Assisted Growth for Ultratrace H2S Detection.

Conductive metal-organic frameworks (c-MOFs) hold promise for highly sensitive sensing systems due to their conductivity and porosity. However, the fabrication of c-MOF thin films with controllable morphology, thickness, and preferential orientation remains a formidable yet ubiquitous challenge. Herein, we propose an innovative template-assisted strategy for constructing MOF-on-MOF (Ni3(HITP)2/NUS-8 (HITP: 2,3,6,7,10,11-hexamino-tri(p-phenylene))) systems with good electrical conductivity, porosity, and solution processability. Leveraging the 2D nature and solution processability of NUS-8, we achieve the controllable self-assembly of Ni3(HITP)2 on NUS-8 nanosheets, producing solution-processable Ni3(HITP)2/NUS-8 nanosheets with a film conductivity of 1.55 × 10-3 S·cm-1 at room temperature. Notably, the excellent solution processability facilitates the fabrication of large-area thin films and printing of intricate patterns with good uniformity, and the Ni3(HITP)2/NUS-8-based system can monitor finger bending. Gas sensors based on Ni3(HITP)2/NUS-8 exhibit high sensitivity (LOD ~ 6 ppb) and selectivity towards ultratrace H2S at room temperature, attributed to the coupling between Ni3(HITP)2 and NUS-8 and the redox reaction with H2S. This approach not only unlocks the potential of stacking different MOF layers in a sequence to generate functionalities that cannot be achieved by a single MOF, but also provides novel avenues for the scalable integration of MOFs in miniaturized devices with salient sensing performance.

Synergistic enhancement of Ni2P anode for high lithium/sodium storage by N, P, S triply-doping and soft template-assisted strategy

Transition metal phosphides have demonstrated excellent performance in the field of energy conversion and storage, where nickel phosphide is one of the most prominent type of phosphides. However, achieving long cycle life with higher specific capacity in the case of Ni2P is still a great challenge. In this study, the composition and structure of Ni2P composites are rationally and precisely adjusted by heteroatoms doping and micelle-assisted methods to attain high capacity for longer cycles at high rate. Among all studied combinations, nickel phosphide particles anchored to triple heteroatom (N, P, S) doped carbon network skeleton (Ni2P@NPS) exhibited specific capacities of 727.3, 586.6, and 321.5 mA h g−1 after 1000 cycles at 1, 2 and 6 A g−1 for lithium-ion batteries (LIBs) and 230.1 mA h g−1 at 1 A g−1 for sodium-ion batteries (SIBs) after 560 cycles. The introduction of heteroatoms optimized the electronic structure of the electrode materials and promoted mass and charge transfer, while triple-heteroatom doped carbon substrates and uniformly dispersed spherical structures formed an active three-dimensional conductive network structure that provided a stronger driving force and richer channels for Li+/Na+ transport. Theoretical calculations showed that the high content of pyrrole nitrogen as well as the additional sulfur ensured improved electrical conductivity and enhanced ion adsorption performance. This study encourages further research into the synergistic effect of N, P, S co-doping materials for improving Li+/Na+ storage and the exploration of other heteroatom co-doping systems.

Activating Excellent Electromagnetic Wave Absorption of Micromorphology-Optimized Cu/C Nanocomposite Fibers via a Metal-Organic Framework Template-Assisted Strategy.

Morphological engineering is crucial for conceiving high-efficiency electromagnetic wave (EMW) absorption materials. However, for carbon fiber-based composites, the management of micromorphology is significantly astricted by complex fabrication. It remains highly challenging to clarify the micromorphological influences on the EMW loss mechanism of carbon fiber-based absorption materials. In this work, micromorphology-optimized Cu/C nanocomposite fibers are prepared by virtue of a metal-organic framework (MOF) template-assisted strategy. Through skillfully grafting the morphology-regulation capacity of MOFs onto composite fibers, the Oswald maturation and particle distribution issues of Cu nanoparticles are settled, and the efficient electron transport pathways are established by the bead-like structure of the fiber matrix. Compared to prepared conventional Cu/C nanocomposite fibers, the MOF template-assisted strategy stimulates a remarkable leap in EMW absorption performance. The minimum reflection loss value of Cu/C-40 can reach -64.5 dB, 15.96 times lower than that of a conventional sample (Cu/C-2). The maximum effective absorption bandwidth extends to 6.08 GHz, contrasting the ineffective performance of Cu/C-2. Systematic research demonstrates that the enabled graphite-catalytic function of Cu nanoparticles collaborated with an optimized conductive network structure plays a pivotal role in creating field-induced leakage currents, facilitating conductive loss, the primary contributor to EMW dissipation. This work establishes a correlation mechanism between micromorphology and EMW loss, presenting a compelling example of customizable carbon fiber-based absorbers.

High-throughput arousing interconnected interfaces for excellent sodium storage chemistry

Heterostructures endow electrochemical hybrids with promising energy storage properties owing to synergistic effects and interfacial interaction. However, developing a facile but effective approach to maximize interface effects is crucial but challenging. Herein, a bimetallic sulfide/carbon heterostructure is realized in a confined carbon network via a high-throughput template-assisted strategy to induce highly active and stable electrode architecture. The designed heterostructures not only yield abundant interconnected Co9S8/MoS2/N-doped carbon (Co9S8/MoS2/NC) heterojunctions with continuous channels for ion/electron transfer but maintain excellent conversion reversibility. Serving as anode for sodium storage, the Co9S8/MoS2/NC framework displayed excellent sodium storage properties (reversible capacity of 480 mAh/g after 100 cycles at 0.2 A/g and 286.2 mAh/g after 500 cycles at 2 A/g). Given this, this study can guide future design protocols for interface engineering by forming dynamic channels of conversion reaction kinetics for potential applications in high-performance electrodes.

Synthesis of Sulfur Vacancy-Bearing In2S3/CuInS2 Microflower Heterojunctions via a Template-Assisted Strategy and Cation-Exchange Reaction for Photocatalytic CO2 Reduction.

The synthesis of the accurate composition and morphological/structural design of multielement semiconductor materials is considered an effective strategy for obtaining high-performance hybrid photocatalysts. Herein, sulfur vacancy (Vs)-bearing In2S3/CuInS2 microflower heterojunctions (denoted Vs-In2S3/CuInS2) were formed in situ using In2S3 microsphere template-directed synthesis and a metal ion exchange-mediated growth strategy. Photocatalysts with flower-like microspheres can be obtained using hydrothermally synthesized In2S3 microspheres as a template, followed by Ostwald ripening growth during the metal cation exchange of Cu+ and In3+. The optimal heterostructured Vs-In2S3/CuInS2 microflowers exhibited CO and CH4 evolution rates of 80.3 and 11.8 μmol g-1 h-1, respectively, under visible-light irradiation; these values are approximately 4 and 6.8 times higher than those reported for pristine In2S3, respectively. The enhanced photocatalytic performance of the Vs-In2S3/CuInS2 catalysts could be attributed to the synergistic effects of the following factors: (i) the constructed heterojunctions accelerate charge-carrier separation; (ii) the flower-like microspheres exhibit highly uniform morphologies and compositions, which enhance electron transport and light harvesting; and (iii) the vs. may trap excited electrons and, thus, inhibit charge-carrier recombination. This study not only confirms the feasibility of the design of heterostructures on demand, but also presents a simple and efficient strategy to engineer metal sulfide photocatalysts with enhanced photocatalytic performance.

Effects of Intrinsic Defects in Pt-Based Carbon Supports on Alkaline Hydrogen Evolution Reaction.

Carbon material has widely been utilized in the synthesis of efficient carbon-supported Pt (Pt/C) catalysts, in which the structural properties greatly influence the electrocatalytic performances of Pt/C catalysts. However, the effects of intrinsic defects in carbon supports on the performance of the alkaline hydrogen evolution reaction (HER) have not been systematically investigated. Herein, porous carbon supports with different degrees of intrinsic defects were prepared by a simple template-assisted strategy, and the resulting samples were systematically studied by various analytical methods. The results suggested that the presence of abundant intrinsic defects (vacancy and topological defects) in the carbon support was advantageous in terms of favoring the dispersion and anchoring of Pt species, promoting electron transfer between Pt atoms and the carbon support, and tuning the electronic states of Pt species. These features improved the HER performance of Pt/C catalysts. Compared to the nontemplate-assisted carbon-supported Pt catalyst (Pt/NTC) with an overpotential of 178 mV, the optimized template-assisted carbon-supported Pt catalyst (Pt/TC) exhibited a lower overpotential of 58 mV at 10 mA cm-2. Besides, the Pt/TC catalyst displayed better HER durability than the Pt/NTC catalyst owing to its strong metal-support interaction. The DFT calculations confirmed the important role played by intrinsic defects (vacancy and topological defects) in stabilizing Pt atoms, with Pt-C3 coordination identified as the most favorable structure for improving the HER performance of Pt. Overall, novel insights on the significant contribution of intrinsic defects in porous carbon supports on the HER performances of Pt/C catalysts were provided, useful for future design and fabrication of advanced carbon-supported catalysts or other carbon-based electrode materials.

Template-assisted strategy for synthesizing transition metal oxyhydroxide for high-efficiency oxygen evolution reaction

Oxyhydroxides have been widely recognized as the true active species for oxygen evolution reaction (OER), while most of them are created via the complicated and time-consuming electrochemical activation process. Here, we develop a facile template-mediated method for directly synthesizing highly active oxyhydroxides toward OER. The optimal FeCoOOH prepared via using Cu2O as a sacrificial template could exhibit outstanding electrocatalytic OER performance, delivering a current density of 10 mA cm−2 with the overpotential of merely 320 mV, and a corresponding Tafel slope of 77.5 mV dec−1. Detailed mechanism study outlines that the extraordinary OER performance of such FeCoOOH originated from the intrinsically high OER activity of oxyhydroxide and the high specific surface area of the particular architecture. This work demonstrates a simple and direct route for the successful fabrication of highly active oxyhydroxides, which may open a new way for the synthesis of other active species.

Polarized emission of Cs3Cu2I5 nanowires embedded in nanopores of an anodic aluminum oxide template.

Due to the intrinsic polarized emission property, polarized emissive materials with anisotropic nanostructures are expected to be potential substitutes for polarizers. Herein, by the template-assisted strategy, well-aligned lead-free metal halide Cs3Cu2I5 nanowire (NW) arrays are fabricated by evaporating the precursor ink in the anodic aluminum oxide (AAO) for polarized emission. The Cs3Cu2I5/AAO composite film emits highly polarized light with a degree of polarization (DOP) of 0.50. Furthermore, by changing the molar ratio of CsI/CuI, the stability of Cs3Cu2I5 precursor inks is improved. Finally, an ultraviolet (UV) light-emitting diode (LED) is adopted to pump the composite film to achieve a blue LED device. The reported Cs3Cu2I5/AAO composite film with highly polarized light emissions will have great potential for polarized emission applications such as liquid crystal display backlights, waveguides, and lasers.

Robust superhydrophobic PVDF membrane constructed by template-assisted strategy via thermally induced phase separation for rapid water-in-oil emulsions separation

The bottlenecks of low separation efficiency and unsatisfactory structural stability restrain the advancement of superhydrophobic membranes in water-in-oil emulsions separation. In this work, a facile template-assisted strategy was proposed to construct the robust membranes by casting the polyvinylidene fluoride (PVDF) solution onto the hot stainless plate with the silicon dioxide (SiO2) suspension sprayed as the template in advance. The underlying merits of SiO2 incorporated for the construction of hierarchical structure characteristics and meanwhile served as the reaction sites for the follow-up fluorinated modification were demonstrated, in terms of developing highly-permeable membrane with super hydrophobicity. Correspondingly, the best performing membrane of M−300F shows the fluxes of 2351 ± 225 L·m−2·h−1 and 2752 ± 210 L·m−2·h−1 in the separation of simulated water-in-toluene and water-in-hexane emulsions, and meanwhile exhibits the water rejection of 98.9 ± 0.6 % and 99.1 ± 0.3 % respectively. Results reported in this work might demonstrate a new insight in constructing superhydrophobic membranes for practical water-in-oil emulsions separation.

Coordinating Etching Inspired Synthesis of Fe(OH)3 Nanocages as Mimetic Peroxidase for Fluorescent and Colorimetric Self-Tuning Detection of Ochratoxin A.

The development of multifunctional biomimetic nanozymes with high catalytic activity and sensitive response is rapidly advancing. The hollow nanostructures, including metal hydroxides, metal-organic frameworks, and metallic oxides, possess excellent loading capacity and a high surface area-to-mass ratio. This characteristic allows for the exposure of more active sites and reaction channels, resulting in enhanced catalytic activity of nanozymes. In this work, based on the coordinating etching principle, a facile template-assisted strategy for synthesizing Fe(OH)3 nanocages by using Cu2O nanocubes as the precursors was proposed. The unique three-dimensional structure of Fe(OH)3 nanocages endows it with excellent catalytic activity. Herein, in the light of Fe(OH)3-induced biomimetic nanozyme catalyzed reactions, a self-tuning dual-mode fluorescence and colorimetric immunoassay was successfully constructed for ochratoxin A (OTA) detection. For the colorimetric signal, 2,2'-azino-bis (3-ethylbenzothiazoline-6-sulfonic acid) diammonium salt (ABTS) can be oxidized by Fe(OH)3 nanocages to form a color response that can be preliminarily identified by the human eye. For the fluorescence signal, the fluorescence intensity of 4-chloro-1-naphthol (4-CN) can be quantitatively quenched by the valence transition of Ferric ion in Fe(OH)3 nanocages. Due to the significant self-calibration, the performance of the self-tuning strategy for OTA detection was substantially enhanced. Under the optimized conditions, the developed dual-mode platform accomplishes a wide range of 1 ng/L to 5 μg/L with a detection limit of 0.68 ng/L (S/N = 3). This work not only develops a facile strategy for the synthesis of highly active peroxidase-like nanozyme but also achieves promising sensing platform for OTA detection in actual samples.

Homogeneous regulation of arranged polymorphic manganese dioxide nanocrystals as cathode materials for high-performance zinc-ion batteries

Rechargeable aqueous zinc-ion batteries have emerged as attractive energy storage devices by virtue of their low cost, high safety and eco-friendliness. However, zinc-ion cathodes are bottlenecked by their vulnerable crystal structures in the process of zinc embedding and significant capacity fading during long-term cycling. Herein, we report the rational and homogeneous regulation of polycrystalline manganese dioxide (MnO2) nanocrystals as zinc cathodes via a surfactant template-assisted strategy. Benefiting from the homogeneous regulation, MnO2 nanocrystals with an ordered crystal arrangement, including nanorod-like polyvinylpyrrolidone-manganese dioxide (PVP-MnO2), nanowire-like sodium dodecyl benzene sulfonate-manganese dioxide and nanodot-like cetyltrimethylammonium bromide-manganese dioxide, are obtained. Among these, the nanorod-like PVP-MnO2 nanocrystals exhibit stable long-life cycling of 210 mAh g−1 over 180 cycles at a high rate of 0.3 A g−1 and with a high capacity retention of 84% over 850 cycles at a high rate of 1 A g−1. The good performance of this cathode significantly results from the facile charge and mass transfer at the interface between the electrode and electrolyte, featuring the crystal stability and uniform morphology of the arranged MnO2 nanocrystals. This work provides crucial insights into the development of advanced MnO2 cathodes for low-cost and high-performance rechargeable aqueous zinc-ion batteries.

Composites of an Epoxy Resin (EP)/PVDF/NiCo-Graphene Nanosheet (GNS) for Electromagnetic Shielding

In this study, a series of three-dimensional (3D) epoxy resin/poly(vinylidene fluoride)/nickel–cobalt alloy–graphene nanosheet (EP/PVDF/NiCo-GNS) composites with high thermal conductivity and electromagnetic interference shielding effectiveness (EMI SE) were successfully prepared using a salt template-assisted strategy. X-ray diffraction analysis (XRD), X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM), and transmission electron microscopy (TEM) analyses jointly presented the successful modification of GNS and in situ growth of NiCo alloy. The cross-sectional morphological observations on the PVDF/NiCo-GNS skeleton and epoxy-based composites clearly showed the successful construction of a honeycomb-like heat conduction network. At a NiCo-GNS loading of 15 wt %, the prepared composites’ EMI SE could reach a value of 34.62 dB. The special structures not only perfected the interconnected thermally and electrically conductive network but also facilitated the multiple internal reflections of electromagnetic waves inside the composites. The present work provides an insight into the design of multifunctional polymer-based composites for electronic 3D encapsulation applications.

Melamine foam-induced isotropic graphite foam for effective thermal management and electromagnetic interference shielding

A series of isotropic graphite foams (GFs) were synthesized using a melamine foam (MF) template-assisted strategy for effective thermal management and EMI SE.

Amorphous zeolite imidazole framework-derived hierarchically porous and multi-catalytic active site bifunctional catalysts for zinc–air batteries

Hierarchical porous Co–NC compounds embedded with CoFe alloys were successfully synthesized by a facile salt template-assisted strategy and exhibited excellent catalytic activity and durability as bifunctional oxygen catalysts for zinc–air batteries.

NaCl template-assisted construction of a CoP-MoP heterostructured electrocatalyst for electrocatalytic nitrogen reduction.

The electrocatalytic nitrogen reduction reaction (NRR) to ammonia is a promising technology to store renewable energy and mitigate greenhouse gas emissions. However, it usually suffers from low ammonia yield and selectivity because of the lack of efficient electrocatalysts. Herein, we report that the construction of metal phosphide heterojunctions is an efficient strategy for NRR activity enhancement. A CoP-MoP heterojunction electrocatalyst, which is fabricated by a facile NaCl template-assisted strategy, exhibits a favorable ammonia yield rate of 77.8 μg h-1 mgcat-1 (38.9 μg h-1 cm-2) and a high faradaic efficiency of 11.16% at -0.50 V versus the reversible hydrogen electrode. The high NRR electrocatalytic activity can be attributed to the electronic coupling effects and interfacial synergistic effects of CoP and MoP at the heterojunction interface, which accelerates the electron transfer rate. Moreover, Mo doping changes the d-band centers of metal sites on the CoP surface, which is conducive to N2 adsorption and promotes N2* adsorption in the competition of occupying active sites, thus inhibiting the HER. This work manifests the high potential of phosphide electrocatalysts and opens an alternative route toward NRR electrocatalysis.

Template-assisted synthesis of isomeric copper(i) clusters with tunable structures showing photophysical and electrochemical properties.

A comparative study of structure-property relationships in isomeric and isostructural atomically precise clusters is an ideal approach to unravel their fundamental properties. Herein, seven high-nuclearity copper(i) alkynyl clusters utilizing template-assisted strategies were synthesized. Spherical Cu36 and Cu56 clusters are formed with a [M@(V/PO4)6] (M: Cu2+, Na+, K+) skeleton motif, while peanut-shaped Cu56 clusters feature four separate PO4 templates. Experiments and theoretical calculations suggested that the photophysical properties of these clusters are dependent on both the inner templates and outer phosphonate ligands. Phenyl and 1-naphthyl phosphate-protected clusters exhibited enhanced emission features attributed to numerous well-arranged intermolecular C-H⋯π interactions between the ligands. Moreover, the electrocatalytic CO2 reduction properties suggested that internal PO4 templates and external naphthyl groups could promote an increase in C2 products (C2H4 and C2H5OH). Our research provides new insight into the design and synthesis of multifunctional copper(i) clusters, and highlights the significance of atomic-level comparative studies of structure-property relationships.

Single-Atom Pd-N4 Catalysis for Stable Low-Overpotential Lithium-Oxygen Battery.

The critical challenge for Li-O2 batteries lies in the large charge overpotential, leading to undesirable side reactions and inferior cycle stability. Single-atom catalysts have shown promising prospects in expediting the kinetics of oxygen evolution reaction (OER) for Li-O2 batteries. However, a present practical drawback is the limited understanding of the correlation between the unique atomic structures and the OER mechanism. Herein, a template-assisted strategy is reported to synthesize atomically dispersed Pd anchored on N-doped carbon spheres as cathode catalysts. Benefiting from the well-defined Pd-N4 moiety, the morphology and distribution of Li2 O2 products are distinctly regulated with optimized decomposition reversibility. Theoretical simulations reveal that the unique configuration of Pd-N4 will contribute to the electron transfer from Pd atoms to the adjacent N atoms, which turns the originally electroneutral Pd into positively charged and downshifts the d-band center and therefore weakens its adsorption energy with the intermediates. The Li-O2 batteries with Pd SAs/NC cathode achieve a charge overpotential of only 0.24V and sustainable low-overpotential cycling stability (500mA g-1 ), and can retain a low charge voltage to a very high capacity of 10 000 mAh g-1 . This work provides some insights into designing efficient single-atom catalysts for stable low-overpotential Li-O2 batteries.

Ultrathin Two-Dimensional Polyoxometalate-Based Metal-Organic Framework Nanosheets for Efficient Electrocatalytic Hydrogen Evolution.

The rational design of 2D polyoxometalate-based metal-organic framework (POMOF) nanosheets on a conductive substrate as a self-supporting electrode is highly attractive but a great challenge. Herein is the first demonstration of POMOF nanopillar arrays consisting of 2D nanosheets as a self-supported electrode for the hydrogen evolution reaction (HER) in acidic conditions. Single-crystal X-ray analysis reveal that our as-prepared 2D [Co2(TIB)2(PMo12O40)]·Cl·4H2O [named CoMo-POMOF; TIB = 1,3,5-tris(1-imidazoly)benzene] crystalline materials are connected by Co-α-Keggin polymolybdate units act as secondary building blocks and TIB as the organic ligands. The 2D CoMo-POMOF nanosheets were successfully arrayed on a conductive nickel foam substrate by a facile CoO nanorod template-assisted strategy. Remarkably, the CoMo-POMOF nanopillar arrays demonstrate superior electrocatalytic performance toward the HER with an overpotential of 137 mV and Tafel slope of 59 mV dec-1 at 10 mA cm-2, which are comparable to those of state-of-the-art POMOF-based electrocatalysts. Density-functional theory (DFT) calculations demonstrate that the exposed bridging oxygen active sites (Oa) of Co-α-Keggin polymolybdate units in CoMo-POMOF optimize the Gibbs free energy of H* adsorption (ΔGH* = -0.11 eV) and increase the intrinsic HER activity.