Piezo-catalysis, which leverages mechanical energy to drive chemical reactions, is emerging as a promising method for sustainable energy production. While the enhancement of piezo-catalytic performance through metal-support interactions is well-documented, the critical influence of the synthesis atmosphere during metal-loaded piezo-catalyst preparation has been a notable gap in the field. To this end, we systematically investigate how different atmospheric conditions during the synthesis of catalysts—without gas flow or with Ar, N₂ and O₂—affect metal dispersion, oxidation states, piezo-carrier dynamics, and electronic structure, and subsequently shape the metal-support interactions and piezo-catalytic activity. ZnO/Au, with Au deposited on ZnO, is selected as the model system, and hydrogen evolution reaction is used as the probe reaction. Our results demonstrate that an oxygen-enriched atmosphere significantly enhances the metal-support interactions, achieving an ultrahigh net hydrogen yield of 16.5 mmol·g⁻¹·h⁻¹ on ZnO/Au, a 3.58-fold increase over pristine ZnO. Specifically, the performance improvements substantially surpass those synthesized under other atmospheric conditions. Conversely, exposure to CO₂ transforms the ZnO support into ZnCO₃, adversely affecting its catalytic activity. These findings reveal the crucial impact of synthesis conditions on piezo-catalyst performance and thereby open new avenues for optimizing catalyst systems for enhanced sustainability.

Flexoelectric and photo-flexoelectricity are scientifically intriguing and hold considerable potential for various applications such as soft strain sensing, photovoltaics, energy harvesting, etc. Among flexoelectric materials, freestanding ferroelectric thin films are believed to have huge flexoelectricity and tunability due to their excellent lattice regulatory freedom and sustainability to larger strain gradients. In this work, we demonstrated a freestanding BiFeO₃(BFO) thin film-based soft strain sensor and explored their flexoelectric coefficient and flexoelectric photovoltaic effect under different strain gradients. Under different bending scales, the photocurrent of the thin film exhibits a step-like variation, indicating that the sensor can measure strain gradient with high sensitivity. These results show the potential application of freestanding ferroelectric films in flexible devices.

Magnesium-based energy materials, which combine promising energy-related functional properties with low cost, environmental compatibility and high availability, have been regarded as fascinating candidates for sustainable energy conversion and storage. In this review, we provide a timely summary on the recent progress in three types of important Mg-based energy materials, based on the fundamental strategies of composition and structure engineering. With regard to Mg-based materials for batteries, we systematically review and analyze different material systems, structure regulation strategies as well as the relevant performance in Mg-ion batteries (MIBs) and Mg-air batteries (MABs), covering cathodes, electrolytes, anodes for MIBs, and anodes for MABs; as to Mg-based hydrogen storage materials, we discuss how catalyst adding, composite, alloying and nanostructuring improve the kinetic and thermodynamic properties of de/hydrogenation reactions, and in particular, the impacts of composition and structure modification on hydrogen absorption/dissociation processes and free energy modification mechanism are focused; regarding Mg-based thermoelectric materials, the relations between composition/structure and electrical/thermal transport properties of Mg₃X₂ (X = Sb, Bi), Mg₂X (X = Si, Ge, Sn) and MgAgSb-based materials, together with the representative research progress of each material system, are summarized and discussed. Finally, by pointing out remaining challenges and providing possible solutions, this review aims to shed light on the directions and perspectives for practical applications of magnesium-based energy materials in the future.

Artificial photosynthesis in carbon dioxide (CO₂) conversion into value-added chemicals attracts considerable attention but suffers from the low activity induced by sluggish separation of photogenerated carriers and the kinetic bottleneck-induced unsatisfied selectivity. Herein, we prepare a new-style Bi/TiO₂ catalyst formed by pinning bismuth clusters on TiO₂ nanowires through being confined by pores, which exhibits high activity and selectivity towards photocatalytic production of CH₄ from CO₂. Boosted charge transfer from TiO₂ through Bi to the reactants is revealed via in situ X-ray photon spectroscopy and time-resolved photoluminescence (PL). Further, in situ Fourier transform infrared results confirm that Bi/TiO₂ not only overcomes the multi-electron kinetics challenge of CO₂ to CH₄ via boosting charge transfer, but also facilitates proton production and transfer as well as the intermediates *CHO and *CH₃O generation, ultimately achieving the tandem catalysis towards methanation. Theoretical calculation also underlies that the more favorable reaction step from *CO to *CHO on Bi/TiO₂ results in CH₄ production with higher selectivity. Our work brings new insights into rational design of photocatalysts with high performance and the formation mechanism of CO₂ to CH₄ for solar energy storage in future.

Fuel cells operated with a reformate fuel such as methanol are promising power systems for portable electronic devices due to their high safety, high energy density and low pollutant emissions. However, several critical issues including methanol crossover effect, CO-tolerance electrode and efficient oxygen reduction electrocatalyst with low or non-platinum usage have to be addressed before the direct methanol fuel cells (DMFCs) become commercially available for industrial application. Here, we report a highly active and selective Mg−Co dual-site oxygen reduction reaction (ORR) single atom catalyst (SAC) with porous N-doped carbon as the substrate. The catalyst exhibits a commercial Pt/C-comparable half-wave potential of 0.806 V (versus the reversible hydrogen electrode) in acid media with good stability. Furthermore, practical DMFCs test achieves a peak power density of over 200 mW cm⁻² that far exceeds that of commercial Pt/C counterpart (82 mW cm⁻²). Particularly, the Mg−Co DMFC system runs over 10 h with negligible current loss under 10 M concentration methanol work condition. Experimental results and theoretical calculations reveal that the N atom coordinated by Mg and Co atom exhibits an unconventional d-band-ditto localized p-band and can promote the dissociation of the key intermediate *OOH into *O and *OH, which accounts for the near unity selective 4e⁻ ORR reaction pathway and enhanced ORR activity. In contrast, the N atom in SAC–Co remains inert in the absorption and desorption of *OOH and *OH. This local coordination environment regulation strategy around active sites may promote rational design of high-performance and durable fuel cell cathode electrocatalysts.

A recent discovery of high-performance Mg₃Sb₂ has ignited tremendous research activities in searching for novel Zintl-phase compounds as promising thermoelectric materials. Herein, a series of planar Zintl-phase XCuSb (X = Ca, Sr, Ba) thermoelectric materials are developed by vacuum induction melting. All these compounds exhibit high carrier mobilities and intrinsic low lattice thermal conductivities (below 1 W·m⁻¹·K⁻¹ at 1010 K), resulting in peak p-type zT values of 0.14, 0.30, and 0.48 for CaCuSb, SrCuSb, and BaCuSb, respectively. By using BaCuSb as a prototypical example, the origins of low lattice thermal conductivity are attributed to the strong interlayer vibrational anharmonicity of Cu–Sb honeycomb sublattice. Moreover, the first-principles calculations reveal that n-type BaCuSb can achieve superior thermoelectric performance with the peak zT beyond 1.1 because of larger conducting band degeneracy. This work sheds light on the high-temperature thermoelectric potential of planar Zintl compounds, thereby stimulating intense interest in the investigation of this unexplored material family for higher zT values.

Recently, the bismuth-rich strategy via increasing the bismuth content has been becoming one of the most appealing approaches to improve the photocatalytic performance of bismuth oxyhalides. However, insights into the mechanism behind the encouraging experiments are missing. Herein, we report the results of the theory-led comprehensive picture of bismuth-rich strategy in bismuth oxyhalide photocatalysts, selecting Bi₅O₇X (X = F, Cl, Br, I) as a prototype. First-principle calculations revealed that the strategy enables good n-type conductivity, large intrinsic internal electric field, high photoreduction ability and outstanding harvest of visible light, and particularly ranked the intrinsic activity of this family: Bi₅O₇F > Bi₅O₇I > Bi₅O₇Br > Bi₅O₇Cl. Designed experiments confirmed the theoretical predictions, and together, these results are expected to aid future development of advanced photocatalysts.

Achieving high thermoelectric performance in thin film heterostructures is essential for integrated and miniatured thermoelectric device applications. In this work, we demonstrate a mechanism and device performance of enhanced thermoelectric performance induced by interfacial effect in a transition metal dichalcogenides-SrTiO₃ (STO) heterostructure. Owing to the formed conductive interface and elevated conductivity, the ZrTe₂/STO heterostructure presents large thermoelectric power factor of 3.7 × 10⁵ μWcm⁻¹K⁻² at 10 K. Formation of quasi-two-dimensional conductance at the interface is attributed for the large Seebeck coefficient and high electrical conductivity, leading to high thermoelectric performance which is demonstrated by a prototype device attaining 3 K cooling with 100 mA current input to this heterostructure. This superior thermoelectric property makes this heterostructure a promising candidate for future thermoelectric device.

Mg₃Sb₂ has attracted intensive attention as a typical Zintl-type thermoelectric material. Despite the exceptional thermoelectric performance in n-type Mg₃Sb₂, the dimensionless figure of merit (zT) of p-type Mg₃Sb₂ remains lower than 1, which is mainly attributed to its inferior electrical properties. Herein, we synergistically optimize the thermoelectric properties of p-type Mg₃Sb₂ materials via codoping of Cd and Ag, which were synthesized by high-energy ball milling combined with hot pressing. It is found that Cd doping not only increases the carrier mobility of p-type Mg₃Sb₂, but also diminishes its thermal conductivity (κ_tot), with Mg_2.85Cd_0.5Sb₂ achieving a low κ_tot value of ~0.67 W m⁻¹ K⁻¹ at room temperature. Further Ag doping elevates the carrier concentration, so that the power factor is optimized over the entire temperature range. Eventually, a peak zT of ~0.75 at 773 K and an excellent average zT of ~0.41 over 300 − 773 K are obtained in Mg_2.82Ag_0.03Cd_0.5Sb₂, which are ~240% and ~490% higher than those of pristine Mg_3.4Sb₂, respectively. This study provides an effective pathway to synergistically improve the thermoelectric performance of p-type Mg₃Sb₂ by codoping Cd and Ag, which is beneficial to the future applications of Mg₃Sb₂-based thermoelectric materials.

Band structure engineering is an effective strategy for the improvement in thermoelectric performance, especially in electrical transport properties. In this work, high pressure is employed to assist Te doping to rapidly realize modulation of band structure in BiCuSe_1-xTe_xO, and then achieving a superhigh carrier mobility of 129.6 cm²V^–1s^–1 due to significant reduction in the effective mass. The experimental observations have been verified by density functional theory (DFT) simulation. Meanwhile, the implementing of high pressure during synthesis process extends the optimization effect of Te doping on carrier-phonon transport of BiCuSeO system. The multiscale microstructures induced by synergistic effect of high pressure and Te content markedly modulate the scattering mechanisms of carriers and phonons, yielding an ultralow thermal conductivity of 0.3 W m^–1K^–1 at 873 K and a moderate effect on low-energy carriers. Ultimately, a maximum zT of 0.86 at 873 K is achieved for BiCuSe_0.8Te_0.2O, ~21% improvement in comparison with the previous reported value for state-of-the-art BiCuSe_1-xTe_xO samples. This study provides a revelation for employing high pressure to manipulate band structure, promoting the effect of heteroatoms doping on the improvement in thermoelectric performance of the BiCuSeO or other systems.