Lead halide perovskite nanocrystals (NCs) have demonstrated great potential as appealing candidates for advanced optoelectronic applications. However, the toxicity of lead and the intrinsic ...instability toward moisture hinder their mass production and commercialization. Herein, to solve such thorny problems, novel lead‐free Cs2AgBiBr6 double perovskite NCs fabricated via a simple hot‐injection method are reported, which exhibit impressive stability in moisture, light, and temperature. Such materials are then applied into photocatalytic CO2 reduction, achieving a total electron consumption of 105 µmol g−1 under AM 1.5G illumination for 6 h. This study offers a reliable avenue for Cs2AgBiBr6 perovskite nanocrystals preparation, which holds a great potential in the further photochemical applications.
Stable lead‐free Cs2AgBiBr6 double perovskite nanocrystals with a cubic shape and an average size of 9.5 nm are successfully synthesized via the hot‐injection route, and are employed as photocatalysts to convert CO2 into solar fuels (CO and CH4). This work offers a reliable avenue for Cs2AgBiBr6 perovskite nanocrystals preparation, which holds a great potential in the further photochemical applications.
Halide perovskite quantum dots (QDs), primarily regarded as optoelectronic materials for LED and photovoltaic devices, have not been applied for photochemical conversion (e.g., water splitting or CO2 ...reduction) applications because of their insufficient stability in the presence of moisture or polar solvents. Herein, we report the use of CsPbBr3 QDs as novel photocatalysts to convert CO2 into solar fuels in nonaqueous media. Under AM 1.5G simulated illumination, the CsPbBr3 QDs steadily generated and injected electrons into CO2, catalyzing CO2 reduction at a rate of 23.7 μmol/g h with a selectivity over 99.3%. Additionally, through the construction of a CsPbBr3 QD/graphene oxide (CsPbBr3 QD/GO) composite, the rate of electron consumption increased 25.5% because of improved electron extraction and transport. This study is anticipated to provide new opportunities to utilize halide perovskite QD materials in photocatalytic applications.
The performances of electron‐transport‐layer (ETL)‐free perovskite solar cells (PSCs) are still inferior to ETL‐containing devices. This is mainly due to severe interfacial charge recombination ...occurring at the transparent conducting oxide (TCO)/perovskite interface, where the photo‐injected electrons in the TCO can travel back to recombine with holes in the perovskite layer. Herein, we demonstrate for the first time that a non‐annealed, insulating, amorphous metal oxyhydroxide, atomic‐scale thin interlayer (ca. 3 nm) between the TCO and perovskite facilitates electron tunneling and suppresses the interfacial charge recombination. This largely reduced the interfacial charge recombination loss and achieved a record efficiency of 21.1 % for n‐i‐p structured ETL‐free PSCs, outperforming their ETL‐containing metal oxide counterparts (18.7 %), as well as narrowing the efficiency gap with high‐efficiency PSCs employing highly crystalline TiO2 ETLs.
A non‐annealed, ultrathin, amorphous metal oxyhydroxide was introduced to suppress interfacial charge recombination and reduce energy loss in electron‐transport‐layer (ETL)‐free perovskite solar cells. The cells achieve a record efficiency of 21.1 %, outperforming their ETL‐containing metal oxide counterparts (18.7 %).
Nanostructural modification and chemical composition tuning are paramount to developing effective non-noble hydrogen evolution reaction (HER) catalysts for water splitting. Herein, we report a novel ...excellent porous molybdenum tungsten phosphide (Mo-W-P) hybrid nanosheet catalyst for hydrogen evolution, which is synthesized via in situ phosphidation of molybdenum tungsten oxide (Mo-W-O) hybrid nanowires grown on carbon cloth. The three-dimensional (3D) hierarchical hybrid electrocatalyst exhibits impressively high electrocatalytic activity with a low overpotential of 138 mV required to achieve a high current density of 100 mA cm-2 and a small Tafel slope of 52 mV dec-1 in 0.5 M H2SO4, which are significantly higher than those of single MoP nanosheets and WP2 nanorods. Such an outstanding performance of the Mo-W-P hybrid electrocatalyst is attributed to the 3D conductive scaffolds, porous nanosheet structure, and strong synergistic effect of W and Mo atoms in Mo-W-P, making it a very promising catalyst for hydrogen production. Our findings demonstrate that careful control over the morphology and composition of the electrocatalyst can achieve highly efficient hybrid electrocatalysts.
Halide perovskite single-crystals have recently been widely highlighted to possess high light harvesting capability and superior charge transport behaviour, which further enable their attractive ...performance in photovoltaics. However, their application in photoelectrochemical cells has not yet been reported. Here, a methylammonium lead bromide MAPbBr
single-crystal thin film is reported as a photoanode with potential application in photoelectrochemical organic synthesis, 2,5-dimethoxy-2,5-dihydrofuran. Depositing an ultrathin Al
O
layer is found to effectively passivate perovskite surface defects. Thus, the nearly 5-fold increase in photoelectrochemical performance with the saturated current being increased from 1.2 to 5.5 mA cm
is mainly attributed to suppressed trap-assisted recombination for MAPbBr
single-crystal thin film/Al
O
. In addition, Ti
-species-rich titanium deposition has been introduced not only as a protective film but also as a catalytic layer to further advance performance and stability. As an encouraging result, the photoelectrochemical performance and stability of MAPbBr
single-crystal thin film/Al
O
/Ti-based photoanode have been significantly improved for 6 h continuous dimethoxydihydrofuran evolution test with a high Faraday efficiency of 93%.
Photocleavage of H2O into clean and storable H2 fuel by photoelectrochemical (PEC) cell is a vital part of the sustainable hydrogen economy. However, thus far one of the limitations confronted by PEC ...cell to preferable performance is the insufficient behavior of photoanode for water oxidation half‐reaction. One of the strategies to elevate the photoanode performance is integrating with an oxygen evolution catalyst (OEC) to remove the bottleneck of the water oxidation kinetics. Herein, an ultrafine cobalt iron oxide (CIO) nanocrystalline is reported as a novel OEC for photoelectrochemical water splitting. The CIO evenly distributing on the surface of hematite nanorod arrays not only greatly facilitates the surface hole injection, but also promotes the charge separation along with passivating the surface states. Such combined effects of CIO finally lead to an impressive 1.71 fold enhancement on the photocurrent density at 1.23 VRHE and ≈170 mV negative shift of onset potential, even overwhelms the commonly utilized Co‐Pi. Along with its excellent long‐term stability, the CIO possesses a great potential application in PEC water splitting devices.
One design for multiple effects: ultrafine CoFe2O4 (CIO) nanoparticles are synthesized as an efficient water oxidation co‐catalyst for α‐Fe2O3 photoelectrode to achieve comprehensive promotions on photoelectrochemical water splitting performances.
Solar-driven CO2 conversion for chemical fuel production has been regarded as an effective strategy to alleviate environmental and energy issues. In this study, we constructed a novel composite ...catalyst film, in which CsPbBr3 nanocrystals (NCs) were loaded on a hierarchical branched ZnO nanowire (BZNW)/macroporous graphene scaffold (CsPbBr3 NC/BZNW/MRGO). This well-designed multi-dimensional architecture rationally integrated the excellent visible-light absorption capability of CsPbBr3 NCs, and fast charge transport and improved CO2 capture ability afforded by ZnO nanowire-branched macroporous graphene. Due to this favorable synergistic effect, a boosted photocatalytic performance was achieved with a photoelectron consumption rate of 52.02 μmol gcat−1 h−1 under visible light irradiation, which is 4.98 and 1.65 times higher than that of CsPbBr3 NC (10.44 μmol gcat−1 h−1) and CsPbBr3 NC/MRGO (31.52 μmol gcat−1 h−1), respectively. Furthermore, desirable CH4 selectivity of up to 96.7% was achieved.
Artificially photocatalytic reduction of CO2 into valuable chemicals, responding to the call of carbon neutral economy, has aroused considerable interests so far. Among those photocatalysts screened, ...an emerging and promising alternative of inorganic CsPbBr3 perovskite has recently been reported. Here, to attain preferable photocatalytic performance, an amorphous‐TiO2‐encapsulated CsPbBr3 nanocrystal (CsPbBr3 NC/a‐TiO2) hybrid is demonstrated through a solution processing strategy. After optimizing the a‐TiO2 matrix amount by tuning the tetrabutyl titanate precursor volume, the CsPbBr3 NC/a‐TiO2 composite exhibits a marvelous 6.5‐fold improvement on the consumption of photoelectrons in photocatalytic CO2 reduction reaction when compared with the individual CsPbBr3 NC. Such significant enhancement is ascribed to the accelerated electron–hole separation and the multiplied CO2 adsorption. Thus, as an available prototype, this work offers a rational encapsulation design for efficient halide perovskite photocatalyst.
A newly designed amorphous‐TiO2‐encapsulated CsPbBr3 nanocrystal is prepared for photocatalytic CO2 reduction reaction, leading to a maximum 6.5‐fold increment on electron consumption by quenching the radiative recombination and increasing CO2 feedstock adsorption. This study emphasizes the pivotal issues in designing halide perovskite photocatalyst and its solution by composite material concept.
Great attention to cost‐effective high‐efficiency solar power conversion of trihalide perovskite solar cells (PSCs) has been hovering at high levels in the recent 5 years. Among PSC devices, ...admittedly, TiO2 is the most widely used electron transport layer (ETL); however, its low mobility which is even less than that of CH3NH3PbI3 makes it not an ideal material. In principle, SnO2 with higher electron mobility can be regarded as a positive alternative. Herein, a SnO2 nanocolloid sol with ≈3 nm in size synthesized at 60 °C was spin‐coated onto the fuorine‐doped tin oxide (FTO) glass as the ETL of planar CH3NH3PbI3 perovskite solar cells. TiCl4 treatment of SnO2‐coated FTO is found to improve crystallization and increase the surface coverage of perovskites, which plays a pivotal role in improving the power conversion efficiency (PCE). In this report, a champion efficiency of 14.69% (Jsc = 21.19 mA cm−2, Voc = 1023 mV, and FF = 0.678) is obtained with a metal mask at one sun illumination (AM 1.5G, 100 mW cm−2). Compared to the typical TiO2, the SnO2 ETL efficiently facilitates the separation and transportation of photogenerated electrons/holes from the perovskite absorber, which results in a significant enhancement of photocurrent and PCE.
SnO2 nanocolloids are synthesized for planar CH3NH3PbI3 perovskite solar cells. A champion efficiency of 14.69% is achieved for the SnO2‐based solar cell, which is superior to the TiO2‐based solar cell (13.38%) due to a higher electron mobility and negative conduction band, facilitating the electron injection, charge separation, and collection, which contribute to the improvement of photovoltaic performance.
Abstract
Akin to single-site homogeneous catalysis, a long sought-after goal is to achieve reaction site precision in heterogeneous catalysis for chemical control over patterns of activity, ...selectivity and stability. Herein, we report on metal phosphides as a class of material capable of realizing these attributes and unlock their potential in solar-driven CO
2
hydrogenation. Selected as an archetype, Ni
12
P
5
affords a structure based upon highly dispersed nickel nanoclusters integrated into a phosphorus lattice that harvest light intensely across the entire solar spectral range. Motivated by its panchromatic absorption and unique linearly bonded nickel-carbonyl-dominated reaction route, Ni
12
P
5
is found to be a photothermal catalyst for the reverse water gas shift reaction, offering a CO production rate of 960 ± 12 mmol g
cat
−1
h
−1
, near 100% selectivity and long-term stability. Successful extension of this idea to Co
2
P analogs implies that metal phosphide materials are poised as a universal platform for high-rate and highly selective photothermal CO
2
catalysis.
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