Peng Zhang

The surface decoration techniques, such as incising-filling, glaze spraying, wood firing, and secondary low-temperature refiring, etc., have been widely used for traditional potteries, such as Jianshui purple pottery. These surface modifications are mainly for artistic expression, whereas functional surface modification has barely been reported. The development of novel coating materials and processes is an alternative path for the innovation of traditional pottery. However, the surface functional materials often peel or detach from the pottery body after high-temperature sintering. It is thus imperative to develop coating materials and processes with robust adhesion and accommodation for secondary functional materials. Through the screening of different ZrO(OH)₂ sols and coating processes, the coating of ZrO(OH)₂ sol on the 800 °C baked Jianshui purple pottery achieved uniform and tight surface coating. Reducing the colloidal particle size and particle concentration in the sol, as well as Y³⁺ doping, is also conductive to the structural stability of the coatings. Additional loading of silver nanoparticles onto the ZrO₂ coating layer effectively endows the pottery with antibacterial performance. The coated samples loaded with silver nanoparticles exhibited an antibacterial rate of 32.7% after accelerated desorption, demonstrating potential for functional pottery applications.

Electrochemical water splitting is a promising method for generating green hydrogen gas, offering a sustainable approach to addressing global energy challenges. However, the sluggish kinetics of the anodic oxygen evolution reaction (OER) poses a great obstacle to its practical application. Recently, increasing attention has been focused on introducing various external stimuli to modify the OER process. Despite significant enhancement in catalytic performance, an in-depth understanding of the origin of superior OER activity contributed by the external stimuli remains elusive, which significantly hinders the further development of highly efficient and durable water electrolyzed devices. Herein, this review systematically summarizes the recent advancements in the understanding of various external stimuli, including photon irradiation, applied magnetic field, and thermal heating, etc., to boost OER activities. In particular, the underlying mechanisms of external stimuli to promote species transfer, modify the electronic structure of electrocatalysts, and accelerate structural reconstruction are highlighted. Additionally, applications of external stimuli in other electrocatalytic reactions are also presented. Finally, several remaining challenges and future opportunities are discussed, providing insights that could further the study of external stimuli in electrocatalytic reactions and support the rational design of highly efficient energy storage and conversion devices.

Cesium carbonate is used to modify the labile PEDOT : PSS into a robust polymer substrate, which suppresses nonradiative recombination and chemical erosion at the buried interface, enabling Sn–Pb perovskite solar cells with >23% efficiency.

Heterostructures are often constructed to modulate the electronic states of the two catalysts, achieving high-performance in alkaline hydrogen evolution reaction (HER). Various mechanisms have been proposed for the heterostructural catalysts, which however awaits further approvement. Herein, a heterostructure composed of Co₂P and CoP was successfully prepared with significantly enhanced HER catalytic activity relative to the endmembers. The ultraviolet photoelectron spectroscopy (UPS) and X-ray photoelectron spectroscopy (XPS) revealed the effective promotion of the self-driven transferring of electrons from CoP to Co₂P and the accumulation of electrons on the P sites in Co₂P due to the strong electronic coupling of built-in electric field in the Co₂P/CoP interface. In situ electrochemical impedance spectroscopy (EIS) and poison experiments confirmed the Heyrovsky step of H* intermediate depleting on electronegative P sites and contributions of both metal and P to the reactivity in the Co₂P/CoP. Density functional theory (DFT) calculations clarify that the electronic structure at interface of the heterojunction significantly weakens the hydrogen adsorption free energy (ΔG_{H* ads}) of P site in Co₂P/CoP to near zero. We also propose an electronic redistribution strategy for heterostructures that activates the multiple routes mechanism and production of more active sites. The working mechanism is expected to be further extended to other transition metal compounds for efficient HER activity.

Electrolytic water splitting is a promising path for the production of clean hydrogen when combined with green electric power, such as photovoltaic and wind power; however, the high current water electrolysis is mainly dependent on the utilization of Pt, Ru, and other expensive materials, while the transition metal-based catalysts still need improvement in electrocatalytic activity and stability. Here, we present the preparation of economic and scalable electrode materials, Nickel-Iron phosphide/Nickel foam (NiFeP/NF), with a hierarchical porous structure for overall water splitting as both the anode and cathode. An overall potential of 1.85 V for the current density of 100 mA cm⁻², and a long lifetime of 700 h, were achieved by using NiFeP/NF as both the anode and cathode. The nanostructures of the composite phosphides were investigated and the spent electrode after long-term electrolysis was characterized to investigate the long-term failure mechanism of the phosphides. Surface shedding and reconstruction theories were proposed for the failure of the NiFeP/NF cathode and anode in long-term electrolysis, respectively. Furthermore, TiO₂ coating was proved to be an efficient strategy to elongate the lifetime of the phosphide electrodes, which shows a slow current decline rate of 0.49 mA·cm⁻² h⁻¹.

Heteroepitaxial Zn-doped p-GaP was grown on (001) GaAs, (001) Si and (111) Si substrates by hydride vapor phase epitaxy for solar-driven photoelectrochemical applications of hydrogen generation by water splitting and CO₂ reduction. Growth of GaP on Si was realized through the implementation of a low-temperature buffer layer, and the morphology and crystalline quality were enhanced by optimizing the precursor flows and pre-heating ambient substrate. The p-GaP/GaAs and p-GaP/Si samples were processed to photoelectrodes with an amorphous TiO₂ coating for CO₂ reduction and a combination of TiO₂ layer and mesoporous tungsten phosphide catalyst for water splitting. P-GaP/GaAs with suitable Zn-doping concentration exhibited photoelectrochemical performance comparable to homoepitaxial p-GaP/GaP for water splitting and CO₂ reduction. Degradation of photocurrent in p-GaP/Si photoelectrodes is observed in PEC water splitting due to the high density of defects arising from heteroepitaxial growth.

An efficient and cost-friendly FePi co-catalyst was generated on an Fe₂O₃/p-Si photocathode for enhancing hydrogen evolution reaction activity, derived from accelerated surface kinetics and efficient separation of photogenerated carriers.