Pyrite Nanoparticles Research Articles

Correction: Sai, R.; Abumousa, R.A. Impact of Iron Pyrite Nanoparticles Sizes in Photovoltaic Performance. Coatings 2023, 13, 167

It has been brought to the authors attention that Figure 1 [...]

Heme protein identified from scaly-foot gastropod can synthesize pyrite (FeS2) nanoparticles.

The scaly-foot gastropod (Chrysomallon squamiferum), which lives in the deep-sea zone of oceans around thermal vents, has a black shell and scales on the foot. Both the black shell and scales contain iron sulfide minerals such as greigite (Fe3S4) and pyrite (FeS2). Although pyrite nanoparticles can be used as materials for solar panels, it is difficult to synthesize stable and spherical nanoparticles in vitro. In this study, we extracted organic molecules that interact with nano-pyrite from the shell of the scaly-foot gastropod to develop a low-cost, eco-friendly method for pyrite nanoparticles synthesis. Myoglobin (csMG), a heme protein, was identified in the iron sulfide layer of the shell. We purified recombinant csMG (r-csMG) and demonstrated that r-csMG helped in the conversion of ferric ions, sulfide ions and sulfur into spherical shaped pyrite nanoparticles at 80°C. To reduce the effort and cost of production, we showed that commercially available myoglobin from Equus caballus (ecMG) also induced the in vitro synthesis of pyrite nanoparticles. Using structure-function experiments with digested peptides, we highlighted that the amino acid sequence of r-csMG peptides controlled the spherical shape of the nanoparticle while the hemin molecules, which the peptides interacted with, maintained the size of nanoparticles. Synthesized pyrite nanoparticles exhibited strong photoluminescence in the visible wavelength region, suggesting its potential application as a photovoltaic solar cell material. These results suggest that materials for solar cells can be produced at low cost and energy under eco-friendly conditions. STATEMENT OF SIGNIFICANCE: Pyrite is a highly promising material for photovoltaic devices because of its excellent optical, electrical, magnetic, and transport properties and high optical absorption coefficient. Almost all current pyrite synthesis methods use organic solvents at high temperature and pressure under reducing conditions. Synthesized pyrite nanoparticles are unstable and are difficult to use in devices. The scaly-foot gastropod can synthesize pyrite nanoparticles in vivo, meaning that pyrite nanoparticles can be generated in an aqueous environment at low temperature. In this study, we demonstrated the synthesis of pyrite nanoparticles using a heme protein identified in the iron sulfide layer of the scaly-foot gastropod shell. These results exemplify how natural products in organisms can inspire the innovation of new technology.

Unveiling the interaction mechanism between facet-dependent pyrite nanoparticles and Cr(VI) under anaerobic environment: adsorption, redox, and phase transformation

The environmental migration and bioavailability of Hexavalent chromium (Cr(VI)) could be affected by facet-dependent pyrite (FeS2) existing in soils and sediments. Conversely, the occurrence state of facet-dependent FeS2 might also be influenced by Cr(VI). However, the complex interactive mechanism at the solid–liquid interface between facet-dependent FeS2 and Cr(VI) still remained ambiguous. Herein, FeS2 nanobelts, FeS2 nanosheets, and FeS2 nanocubes with corresponding dominant facets of (−110), (001), (100)/(210) were prepared. The adsorption and reduction experimental results reflected that Cr(VI) species were predominantly adsorbed and a portion of them was reduced to Cr(III) at the FeS2 interfaces. In particular, the adsorption efficiency of Cr(VI) on (001) facet was 1.39 and 4.69 times than those on (−110) and (100)+(210) facets, respectively. The results of in situ Attenuated Total Reflectance Fourier Transform Infrared spectroscopy (ATR-FTIR) measurements and Density Functional Theory (DFT) calculations suggested that bidentate binuclear (BB) coordinated chromates were generated on the (001) facet while monodentate mononuclear (MM) coordinated chromates were formed on (−110), (100), and (210) facets. Due to the stronger adsorption energy and more stable coordination mode of BB for Cr(VI) species on (001) facet, FeS2 NS exhibited higher efficiency of Cr(VI) removal and reduction compared with FeS2 NB and FeS2 NC. In addition, partial FeS2 particles were proved to be transformed to goethite under the effect of Cr(VI). Owing to the stronger adsorption of Cr(VI) species on (001) facet, FeS2 NS also had a faster phase transformation rate than FeS2 NB and FeS2 NC. Above results all reflected the good structure–reactivity relationships between the FeS2 facets and the Cr(VI) removal efficiency as well as the phase transformation of FeS2 particles.

Impact of Iron Pyrite Nanoparticles Sizes in Photovoltaic Performance

With rising energy demand and depleted traditional fuels, solar cells offer a sustainable and clean option. In recent years, and due to its acceptable band gap, high absorption coefficient, and inexpensive cost, iron pyrite (FeS2) is a popular material for solar cells. Earth abundance and nontoxicity further boost its photovoltaic possibilities. The current study examined the influence of sulfurization at 350–400 °C on iron pyrite layers fabricated using spray pyrolysis. The morphology and size from TEM confirmed the XRD results of synthesizing a pyrite FeS2 with an average particle size of 10–23 nm at 350–400 °C, respectively. The direct band gap calculated by DFT as a function of temperature was found to be consistent with the experimental findings, 0.87 eV (0.87) and 0.90 eV (0.95) at 350 °C and 400 °C, respectively. We found high-performing photovoltaic cells on ITO/ZnO/FeS2/ MoO3/Au/Ag, obtained with an excellent quality of nanoparticles and nanostructures of FeS2 pyrite, which improved with the method of preparation and growth parameters.

The Role of the Graphene Oxide (GO) and PEO Treated-Zinc Oxide (ZnO/PEO) Intermediate Electrode Buffer Layer in Vacuum-Free Quantum Dots Solar Cell

The vacuum-free quantum dots solar cell (VFQDSC) was fabricated without using any vacuum process. The spherical iron pyrite (FeS2) nanoparticles (SNPs) and ZnO nanoparticles (NPs) were synthesized and characterized. In the device structure, FeS2 SNPs were used as an acceptor material (n-type), and the low band gap polymer of poly[4,8-bis(2-ethylhexyloxyl)benzo[1,2-b:4,5-b′]-dithiophene-2,6-diyl-alt-ethylhexyl-3-fluorothieno[3,4-b]thiophene-2-carboxylate-4,6-diyl] (PBT7) was used as a donor material (p-type). In this study, we first applied the graphene oxide (GO) as the hole transport buffer layer (HTBL) and zinc oxide (ZnO) as an electron transport buffer layer (ETBL), which were considered to improve the charge transportation efficiency of the device’s system. The device with the structure of the Glass/ITO/HTBL/FeS2 SNPs, PBT7/ ETBL/E-GaIn were fabricated with a maximum power conversion efficiency (PCE) of 3.6%.

Differential Behavior of Metal Sulfides in Hydrothermal Plumes and Diffuse Flows

Extensive sampling of high-temperature hydrothermal fluids and diffuse flows within <2 m of the vent orifices at the 9°50′N East Pacific Rise (EPR) hydrothermal vent field reveals formation of nanoparticulate phases and rapid precipitation/aggregation of metal sulfide minerals upon mixing of vent fluid with ambient seawater. Here, we characterize metal sulfide phases via scanning and transmission electron microscopy (SEM, TEM) in addition to quantifying the concentrations of major and trace metals in filtered and unfiltered fluid samples. Analyses demonstrate that, despite coprecipitation in phases such as chalcopyrite, iron speciation and transport is decoupled from that of copper and zinc. We observe the formation of ∼10–500 nm diameter (nano)particulate Zn and Cu sulfide phases that are near-quantitatively removed by filtration. Iron sulfides, conversely, are typically present in SEM images as larger particles up to tens of microns in diameter. Few small nanoparticles (20–100 nm diameter) are captured on the filter, but determination of nitric-acid-soluble iron in 0.2 μm filtered samples indicates the presence of pyrite nanoparticles. Physical mixing and temperature play a larger role in determining the extent of nanoparticulate pyrite formation than fluid chemistry. In diffuse flow environments, Fe and Cu more commonly co-occur as aggregates of very small crystallites, with the Zn sulfide phases occurring separately. Sample pH and the ZPC (zero point of charge) of metal sulfides exhibit chemical control on nanoparticle and large particle formation versus aggregation. The concentrations of the additional trace metals analyzed vary between vent sites, despite the short distances between the sites and likely similar magmatic sources. Measured trace metal concentrations highlight the importance of diffuse flow systems in hydrothermal metal emissions. These near-vent behavioral differences have implications for the long-distance transport of metals away from vent fields in buoyant and nonbuoyant plumes.

Electrocatalytic N2 Reduction on FeS2 Nanoparticles Embedded in Graphene Oxide in Acid and Neutral Conditions

The development of stable, low-cost, and highly efficient electrocatalysts for the N2 reduction reaction (NRR) process is challenging but crucial for ammonia production. Herein, we demonstrate the synthesis of pyrite nanoparticles wrapped by graphene oxide (FeS2@GO) acting as a highly efficient NRR catalyst in a wide pH range. The FeS2 nanoparticles are uniformly dispersed across the GO nanosheet, thus leading to the fine exposure of active sites, the promotion of charge transfer, and the increment of a contact surface area, which are all beneficial for a desired catalyst. In the meantime, the low-coordinated Fe atoms are activated as highly active sites, which is in favor of the enhanced electrochemical performance for the NRR. Furthermore, density functional theory (DFT) calculations illustrated that the high activity of N2 reduction over the FeS2@GO catalyst arises from the well-exposed Fe active sites and the increment of charge density at the valence band edge. Benefiting from the well-optimized interface, the barrier of the addition of the first hydrogen atom to N2 forming *NNH species as the potential-determining step is as low as 0.93 eV in N2 electroreduction. The electrochemical test results reveal that, as expected, FeS2@GO exhibits high Faradaic efficiencies (4.7% in 0.1 M HCl solution and 6.8% in 0.1 M Na2SO4 solution) and advanced NH3 yields (78.6 and 27.9 μg h-1 mgcat.-1 in 0.1 M HCl and 0.1 M Na2SO4 solutions, respectively) in both acid and neutral conditions. This work offers a new avenue for exploring novel electrocatalysts, which has great promise to accelerate the practical application of the NRR.

FeS2 loading on chlorinated carbon nanotubes surface triggered by sulfur addition and their use as electrocatalyst for ORR

Herein, we report on the synthesis of chlorinated sulfur doped carbon nanotubes (SClCNTs) with excellent oxygen reduction reaction (ORR) activity using the pyrolysis and thermal annealing methods. The morphology and quality of the materials produced were dependent on the synthesis method used. The pyrolysis of acetylene over a solution mixture of dichlorobenzene and thiophene resulted in the poisoning of the catalyst and inhibition of CNT growth. Thermal annealing of ClCNTs in the presence of sulfur at various temperatures (800 °C–1000 °C) resulted in production of SClCNTs with increased density. Materials produced at 800 °C revealed formation of metal particles clustered at the surface of the SClCNTs, whilst those produced at 900 and 1000 °C appeared much cleaner, with evidence of well-defined cube-shaped metal nanoparticles decorated at their surface. XRD and XPS revealed the identity of the metal nanoparticles as pyrite (FeS2). The formation of this pyrite nanoparticles was thought to have been initiated by the presence of defects on the walls of the ClCNTs because of chlorine incorporation. The formation of FeS2 nanoparticles was explained using the vapor-liquid-solid process. The enhanced graphitization of carbon materials due to loading of FeS2 nanoparticles on their surface was confirmed by Raman spectra analysis. The ORR activity was greatly enhanced after addition of sulfur into the ClCNTs, the greatest enhancement was observed for materials produced at 900 °C, annealing temperature.

Pyrite nanoparticles derived from mine waste as efficient catalyst for the activation of persulfates for degradation of tetracycline

Pyrite mine waste was used as a non-toxic and natural catalyst for the activation of peroxydisulfate (PDS) and peroxymonosulfate (PMS) to oxidize tetracycline (TTC), one of the most extensively used antibiotics worldwide, in contaminated water. The results demonstrated that PMS was activated more effectively than PDS by using pyrite. Scavenging experiments indicated that both OH and SO4− were the main oxidative species in the pyrite/PMS process, while SO4− was more dominant. A high degradation of 98.3 % and significant mineralization (up to 46 %) of TTC (50 mg/L) were achieved using pyrite activated PMS at a reaction time of 30 and 60 min, respectively. In-vivo toxicity of raw and pyrite/PMS treated TTC solutions was evaluated using biochemical and histopathological assays. The results revealed that the pyrite/PMS process significantly decreased the nephrotoxicity (90 %) and hepatotoxicity (85 %) effect of TTC. Catalyst reusability was evaluated under cycling conditions. No significant decrease in process efficiency was measured between the first and fourth cycle (<3% decrease in TTC removal). In conclusion, mine waste pyrite nanoparticles can be considered as a non-toxic and clean catalyst to activate PMS for an effective detoxification, degradation, and intermediate mineralization of TTC, as a refractory water pollutant.

Use of mine waste for H2O2-assisted heterogeneous Fenton-like degradation of tetracycline by natural pyrite nanoparticles: Catalyst characterization, degradation mechanism, operational parameters and cytotoxicity assessment

Degradation of tetracycline (TTC) with a heterogeneous Fenton-like pyrite/H 2 O 2 process by pyrite from mine waste as a mineral catalyst was investigated. The study focused on identifying the main oxidizing agents and degradation mechanisms along with operational variables including solution pH, pyrite and H 2 O 2 concentration, contact time, solution temperature, and initial TTC concentration. Catalyst characterization tests revealed that pyrite is a mesoporous powder with a high degree of FeS 2 purity. Radical scavenger tests demonstrated that • OH was the main oxidizing agent generated by both solution and surface phase reactions. During the pyrite/H 2 O 2 process, more than 85% of TTC was mineralized in 60 min and the maximum TTC removal was attained in the solution at an acidic pH value (4.1). The most abundant transformation products of TTC, formed by the attack of • OH radicals, were simple chain carboxylic acids. Cultured cells of human embryonic kidney (HEK) were used for the cytotoxicity assessment of raw and pyrite/H 2 O 2 treated TTC solutions. The results illustrated that the viability of HEK cells was enhanced considerably after treating TTC solutions under optimal conditions. Accordingly, pyrite originating from mine waste is a practically effective and cost-effective catalyst in heterogeneous Fenton-like systems for mineralization and degradation of emerging contaminants such as antibiotics. • Nano-sized pyrite with highly purity prepared from mine waste was used as a mineral catalyst. • Hydroxyl radicals are the main oxidants for TTC degradation in the pyrite/H 2 O 2 process. • Both solution and surface sulfur-defects are responsible for. • OH generation • The pyrite/H 2 O 2 process acquired comprehensive removal of 50 mg/L TTC and over 85% mineralization during 60 min. • The pyrite/H 2 O 2 process is an effective AOP for removing emerging contaminants.

In situ observations of thermally induced phase transformations in iron sulfide nanoparticles

Iron pyrite (FeS2) exhibits dynamic thermal stability and represents an ideal model system to probe complex phase transformations in materials. At elevated temperatures, the sublimation of S atoms from the FeS2 lattice results in a phase transformation to one of the many polymorphic forms of pyrrhotite, i.e., from Fe1-XS (where 0 ≤ X < 0.2) to stoichiometric FeS. The complex nature of this phase transformation remains relatively unexplored at the nanoscale. Here, we use in situ transmission electron microscopy (TEM) and in situ X-ray diffraction (XRD) to observe the phase transformation of ~150 nm pyrite nanoparticles to pyrrhotite in vacuum. Although the overall shape of the nanoparticles remains cubic, the crystal structure of the nanoparticles changes from cubic pyrite to hexagonal pyrrhotite at ~400–450oC, which is ~100–150oC lower than reported values of bulk pyrite. Interestingly, our in situ observations do not evidence a core-shell transformation model which has been reported for the phase transformation of bulk pyrite to pyrrhotite, indicating the role of shorter length scales for diffusion in nanoparticles, as well as the role of S vacancies that facilitate faster atomic diffusion and rearrangements. In addition, the heating ramp rate was found to influence the phase transition temperature with lower temperatures of transformation seen for higher heating rates indicating the role of kinetic effects on phase transformation. We expect our detailed insights will help advance the use of FeS2 nanoparticles in high-temperature applications including catalysis and high-temperature batteries.

Green and simple preparation of carbon-coated iron pyrite thin films for solar cells application

Carbon-coated iron pyrite (FeS2@C) was prepared by a green and simple method. The utilization of an amorphous carbon-shell layer formed from a glucose source coated on the surface of core-pyrite nanoparticles. The FeS2@C thin film was formed by coating synthesized iron pyrite nanoparticles with a carbon layer and depositing the carbon-coated iron pyrite on a fluorine-doped tin oxide (FTO) substrate by spin-coating. The morphological, structural, and chemical composition properties of FeS2@C film was measured and characterized. Devices with the structure of FTO/TiO2/redox electrolyte/counter electrodes (FeS2@C, pristine FeS2, and Pt)/FTO were fabricated. The power conversion efficiency (PCE) of the FeS2@C-device (PCE ~ 6.94%), the pristine FeS2-device (PCE ~ 5.69%), the Pt-device (PCE ~ 6.48%). The improving of the device performance indicated that the FeS2@C thin film can be a good counter electrode (CE) for the performance of dye-sensitized solar cells (DSSCs).

Iron and sulfide nanoparticle formation and transport in nascent hydrothermal vent plumes

Deep-sea hydrothermal vents are a significant source of dissolved metals to the global oceans, producing midwater plumes enriched in metals that are transported thousands of kilometers from the vent source. Particle precipitation upon emission of hydrothermal fluids controls metal speciation and the magnitude of metal export. Here, we document metal sulfide particles, including pyrite nanoparticles, within the first meter of buoyant plumes from three high-temperature vents at the East Pacific Rise. We observe a zone of particle settling 10–20 cm from the orifice, indicated by stable sulfur isotopes; however, we also demonstrate that nanoparticulate pyrite (FeS2) is not removed from the plume and can account for over half of the filtered Fe (≤0.2 µm) up to one meter from the vent orifice. The persistence of nanoparticulate pyrite demonstrates that it is an important mechanism for near-vent Fe stabilisation and highlights the potential role of nanoparticles in element transport.

Field-scale bioremediation of arsenic-contaminated groundwater using sulfate-reducing bacteria and biogenic pyrite

This research demonstrates that biogenic pyrite formed by stimulation of indigenous sulfate-reducing bacteria (SRB) in a natural aquifer can remove dissolved arsenic from contaminated groundwater under strongly reducing conditions. SRB metabolism led to the precipitation of biogenic pyrite nanoparticles capable of sorbing and co-precipitating arsenic. The field site is an industrial site where shallow groundwater in an unconfined sandy aquifer is contaminated by arsenic. Therefore, biodegradable organic carbon, ferrous iron, sulfate, and fertilizer were injected into groundwater and SRB metabolism began about 1 week later. Microscopic, X-ray diffraction, X-ray fluorescence, and electron microprobe analyses confirm the bio-mineralization of pyrite and over time, pyrite nanoparticles grew to form well-formed crystals (1–10 µm in diameter) or spherical aggregates that contain 0.05–0.4 wt. % arsenic, indicative of their capacity to sequester arsenic. Consequently, dissolved arsenic decreased from its initial concentration of 0.3–0.5 mg/L to below the regulatory clean-up standard for the site of 0.05 mg/L in three downgradient wells in a matter of weeks after injection. The main sequestration stage, with total arsenic removal rates greater than 90%, lasted for at least 6 months until the arrival and mixing of untreated groundwater from upgradient. Treated groundwater with most active bacterial sulfate reduction became enriched in heavy 34S (range from 2.02 to 4.00 ‰) compared to unaffected well water (0.40–0.61 ‰). One to three orders of magnitude increases in SRB cells were observed in treated wells for at least 2 months after injection. For a full-scale remediation, the injection of solution should start at positions hydrologically upgradient from the major plume and proceed downgradient. If needed, aquifers may be repeatedly amended with biodegradable organic carbon to reestablish the reducing conditions that favor arsenic sequestration.

Bioremediation of arsenic-contaminated groundwater by sequestration of arsenic in biogenic pyrite

Pyrite (FeS2) is the most common sulfide mineral in the Earth's crust, and it commonly contains minor amounts of arsenic. Here we show that authigenic pyrite can remove arsenic from contaminated groundwater and this can be used as a new and relatively inexpensive remediation process. Laboratory batch experiments presented show that fine-grain natural pyrite is an effective sorber of dissolved arsenic. Arsenic sorption onto pyrite is shown to increase with increasing pH, particularly at pH > 5 and at elevated dissolved arsenic concentration. We also present results from a field experiment at an arsenic-contaminated industrial site, which demonstrates the results of stimulation of natural sulfate-reducing bacteria in groundwater by injection of a labile organic carbon source, iron, and sulfate. Within a week, bacterial sulfate reduction triggered the formation of biogenic pyrite nanoparticles, which sequestered arsenic by adsorption and co-precipitation. Microscopic and X-ray diffraction analyses confirmed that pyrite was the only iron-sulfide formed, and that no arsenic-only sulfide phase precipitated (e.g. orpiment or realgar). Pyrite occurs as either 1–10 μm euhedral crystals or similar-sized framboids both of which contain 500–4000 mg/kg arsenic. As a result, dissolved arsenic decreased from its initial concentration of 0.3–0.5 mg/L to below the regulatory clean-up standard for the site of 0.05 mg/L in a matter of weeks. In addition to the potential of this technique to remediate anthropogenic arsenic contamination, it is possible that it can be modified to inexpensively treat individual small drinking-water wells contaminated by natural sources of arsenic in many developing nations.

PH-dependence on HER electrocatalytic activity of iron sulfide pyrite nanoparticles

Iron sulfide pyrite (FeS2) nanoparticles are investigated for the electrocatalysis of hydrogen evolution reaction (HER) at pH values ranging from 0.3 to 13. It is evidenced that HER can be performed at any pH, showing remarkable robustness and stability for more than 24 h. The catalytic mechanism for HER by pyrite nanoparticles changes over the pH range, with a pH-dependent behavior below pH 5 and a pH-independent behavior above pH 5.

Facile synthesis of pyrite (FeS2/C) nanoparticles as an electrode material for non-aqueous hybrid electrochemical capacitors.

Pyrite (FeS2) is a promising electrode material for lithium ion batteries (LIBs) because of its high natural availability, low toxicity, cost-effectiveness, high theoretical capacity (894 mA h g-1) and high theoretical specific energy density (1270 W h kg-1, 4e-/FeS2). Nevertheless, the use of FeS2 in electrochemical capacitors was restricted due to fast capacity fading as a result of polysulfide (S/Sn2-) formation during the initial electrochemical cycling. In order to avoid the formation of polysulfides, we employed the strategy of utilizing an ether based electrolyte (1.0 M lithium bis(trifluoromethanesulfonyl)imide (LiTFSI)/diglyme (DGM)). Herein, we introduce FeS2/C as the Faradaic electrode for a non-aqueous hybrid electrochemical capacitor (NHEC) in combination with activated carbon (AC) as a non-Faradaic electrode, and 1.0 M LiTFSI/DGM as a non-aqueous electrolyte. Specifically, FeS2/C nanoparticles have been prepared via the sulfidation of a room temperature synthesized Fe-based MOF (metal organic framework) precursor. The fabricated FeS2/C∥AC NHEC, operating within the chosen voltage window of 0-3.2 V, delivered energy densities in the range of 63-9 W h kg-1 at power densities of 152-3240 W kg-1. Remarkable cycling stability with stable energy density retention for 2500 cycles at high power densities (729, 1186 and 3240 W kg-1) was observed.

Front Cover: Prussian Blue‐Derived Synthesis of Hollow Porous Iron Pyrite Nanoparticles as Platinum‐Free Counter Electrodes for Highly Efficient Dye‐Sensitized Solar Cells (Chem. Eur. J. 54/2017)

Front Cover: Prussian Blue‐Derived Synthesis of Hollow Porous Iron Pyrite Nanoparticles as Platinum‐Free Counter Electrodes for Highly Efficient Dye‐Sensitized Solar Cells (Chem. Eur. J. 54/2017)

Prussian Blue‐Derived Synthesis of Hollow Porous Iron Pyrite Nanoparticles as Platinum‐Free Counter Electrodes for Highly Efficient Dye‐Sensitized Solar Cells

AbstractInvited for the cover of this issue is the group of Kuo‐Chuan Ho and Kevin C.‐W. Wu at the National Taiwan University. The image depicts the hollow porous iron pyrite nanoparticles which are deposited on the conducting substrate as the counter electrode (CE) in a dye‐sensitized solar cell (DSSC). Iron pyrite, with a hollow porous structure, offers a high surface area for the reduction of the triiodide ions. The DSSC directly converts the sunlight into electric power, which could power the flashlight without pollution. It is expected that the DSSC will emerge as a new class of low cost energy conversion device. Read the full text of the article at 10.1002/chem.201702687.

Prussian Blue‐Derived Synthesis of Hollow Porous Iron Pyrite Nanoparticles as Platinum‐Free Counter Electrodes for Highly Efficient Dye‐Sensitized Solar Cells

Iron pyrite has long been an attractive material for environmental and energy applications, but is hampered by a lack of control over morphology and purity. Hollow porous iron pyrite nanoparticles were synthesized by a direct sulfurization of iron oxide derived from Prussian blue. The high efficiencies of these hollow porous iron pyrite nanoparticles as effective dye-sensitized solar cell counter electrodes were demonstrated, with an efficiency of 7.31 %.