Application of Halide Perovskite Nanocrystals in Solar‐Driven Photo(electro)Catalysis

Abstract

Global warming and ecosystems contamination by fine chemicals industry have motivated to explore and develop cleaner and lower cost strategies for the energy conversion and transformation of organic compounds. [1,2] Solar-driven catalysis via photo(electro)catalysis (PEC) has emerged as a promising route to store sunlight into chemical bonds. Commonly, PEC water splitting has been studied as an approach to reduce H þ to produce green hydrogen with the oxygen evolution reaction (OER) as electron donor. As this reaction is kinetically very demanding, water can be substituted by organic compounds as electron donors due to their faster oxidation kinetics. This would increase the H 2 evolution kinetics while concomitantly producing high added-value chemicals, remediating industrial wastewaters, [3][4][5][6][7][8] and making use of semiconductor materials with highly oxidizing/ reducing power. [8,9] In a simple manner, when a semiconductor is illuminated with an energy equal or higher than its bandgap, charge carrier photogeneration and separation is promoted. Photogenerated holes are formed in the valence band (VB), where oxidation reactions take place, while electrons with higher free energy are located in the conduction band (CB) to trigger reduction reactions. [9][10][11] This is the basis of photocatalytic (PC) reactions led through nanoparticle system (Figure 1A). Then, when the photomaterial is deposited in a conducting substrate, PEC oxidation and reduction reactions can be carried out in separate compartments. [9,12,13] Here, one type of photocarriers migrate to the photoelectrode surface to conduct an interfacial PEC semireaction, while the other kind of photocarrier is transported through the external circuit to a counter electrode and perform the complementary PEC semireaction (Figure 1B). [9] Metal oxides, chalcogenides, and heterojunctions based on these materials have attracted significant attention as photocatalysts due to their wide gamut of low-cost synthetic protocols available for their preparation and facile charge carrier extraction [9,10,[13][14][15][16] Although metal oxide photoelectrodes show a high performance under UV light, high stability, and low toxicity in some cases, they are often limited by their poor light harvesting efficiency toward near-infrared wavelengths. Additionally, metal oxide photoelectrodes tend to exhibit a fast carrier recombination as well as poor charge accumulation/transport kinetics, hindering their applicability in solar water splitting applications. [10,17,18] In the case of chalcogenides, their superior optoelectronic properties are in contrast with the low stability promoted by their fast photodegradation. To reduce photodegradation and charge carrier recombination and to overcome charge transport/accumulation kinetic limitations, inner-sphere redox couples and organic substrates are commonly used to accelerate

Improving the Stability of Halide Perovskites for Photo‐, Electro‐, Photoelectro‐Chemical Applications

“…The photocarriers will then migrate to the photoelectrode through the external circuit and conduct the corresponding interfacial half reaction. [261] Most of HPs, which are regarded as promising photomaterials for photoelectrocatalytic reactions, are unstable under ambient conditions, but surprisingly, the vacancy-ordered Cs 2 PtI 6 -based photoanode prepared by Hamdan et al exhibited striking stability (>12 h) and decent photoelectrochemical activity (0.8 mA cm −2 at 1.23 V) for photoelectrochemical oxygen evolution without any protection layers. [7] As a typical all-inorganic halide perovskite, CsPbBr 3 has been applied in photoelectrocatalytic applications in recent years (Table 6).…”

“…[276] Besides, epoxy resin [277] or UV-curing resin [1] was usually to seal the perovskite-based photoelectrode to further protect against water erosion (Figure 18d, e). Noticeably, [261] Copyright 2020, Elsevier. c) Schematic illustration of photoelectrochemical HI splitting over MAPbI 3 /TNA/c-TiO 2 /FTO photoelectrode (TNA = TiO 2 nanorod array).…”

Efficient Ligand Passivation Enables Ultrastable CsPbX3 Perovskite Nanocrystals in Fully Alcohol Environments

“…In this context, recent alternatives such as ligand passivation of PNCs with some robust ligands such as sulfobetaines, [24][25][26] lecithin, [27] aminoacids, [28,29] bidentate species, [30] alkylphosphines, [31,32] among others, can replace conventional oleic acid (OA) and oleylamine (OLA) to increase the PL properties and air-stability of the PNCs. [33] Even though these ligands can solve the actual drawbacks related to the structural instability of the PNCs, it seems that they are not hydrophobic enough to avoid the material degradation. This fact makes that ligand surface modification to produce highly stable PNCs in polar environments is not a widely exploited topic, yet.…”

A halide perovskite/lead sulfide heterostructure with enhanced photoelectrochemical performance for the sensing of alkaline phosphatase (ALP)

“…1 A lot of halide perovskite materials have been utilized in colorimetric, 2 fluorescence, 3 electrochemical, 4 and photoelectrochemical (PEC) biosensors 5 benefiting from their high absorption coefficient, low excitation banding energy, high quantum yields and high charge-carrier mobility. 6 In particular, with high photoelectric conversion efficiency and impressive ionic conductivity, halide perovskite materials have been applied in photovoltaic cells, 7 light-emitting diodes, 8 and photoelectric catalysis applications, 9 as well as the photoelectric active material in photoelectrochemical biosensing applications. Despite their promising applications in biosensing, the halide perovskite materials are severely limited in bioanalysis due to their lack of stability, especially in aqueous solution.…”