Facile Fabrication of Hybrid Perovskite Single‐Crystalline Photocathode for Photoelectrochemical Water Splitting

Abstract

Recently, beyond various optoelectronic devices, lead halide perovskites have emerged as promising candidates for high‐performance photocatalysts owing to their excellent optoelectronic properties. However, most previous works on perovskite photocatalysts mainly used the forms of nanocrystals that need the perovskite‐saturated electrolyte or polycrystalline thin films that still suffer from the instability in water and low performance. Herein, the synthesis of high‐quality hybrid perovskite single crystals and their implementation as photocathodes for water splitting with a simple device structure are reported on. Optimized perovskite crystals exhibit a good water splitting photocurrent density of −0.51 mA cm−2 at 0 V versus reversible hydrogen electrode (RHE) under visible light illumination. Moreover, such devices as the p‐type photocathodes show improved stability, exhibiting no obvious decrease over 600 s. This work highlights the great potential of hybrid perovskite single crystals for photocatalyst applications in aqueous solution.

Synergistically Interface-Engineered Inorganic Halide Perovskite Photocathodes for Photoelectrochemical CO2 Reduction

“…We then compared the charge-transport properties of the photoelectrodes performing the space-charge-limited current (SCLC) measurements in the dark condition. − There are normally three regions in the measured SCLC curve; at the intermediate voltages, the I – V curve has the slope larger than 2 in the log coordinate system, in which all of the available trap states were filled by the injected carriers. The voltage that started the trap-filled region can be called trap-fill limit voltage V TFL , which is proportional to the trap density n trap according to the equation n trap = 2 ε ε 0 V TFL / e d 2 where ε is the dielectric constant of the photoelectrode material, ε 0 is the vacuum permittivity, e means the electronic charge, and d is the thickness of the material.…”

Sizing Up Metal Halide Perovskite Photocatalysts: From Nano to Bulk

“…[36] These materials can be either polycrystalline or single crystalline, and these two configurations will be discussed separately. Note that both polycrystalline films and single crystals [81,82] have also been integrated into water splitting systems as either photovoltaic materials or photoelectrodes in photoelectrochemical (PEC) cells, but discussion of these types of devices is beyond the scope of this Perspective, and readers are directed to reviews of perovskite materials in PEC cells. [83][84][85][86] The use of bulk perovskites as photocatalysts has been rather limited despite their enhanced stabilities compared to PNCs.…”

Halide perovskite single crystals: growth, characterization, and stability for optoelectronic applications

“…(3) Expansion of applications: beyond various optoelectronic devices, perovskite single crystals have been used as photocatalysts, and implemented as highly stable photocathodes for water splitting. 189 With various electron and hole transfer layers or structural configurations, perovskite single-crystal photocatalysts show an excellent development potential. Recently, perovskite single crystals have been exploited as artificial synapses for realizing neuromorphic and bioinspired intelligent systems.…”