Promoted interfacial charge transfer by coral-like nickel diselenide for enhanced photocatalytic hydrogen evolution over carbon nitride nanosheet

Seeking an efficient and non-precious co-catalyst for g-C₃N₄ (CN) remains a great demanding to achieve high photocatalytic hydrogen generation performance. Herein, a composite photocatalyst with high efficiency was prepared by modifying CN with coral-like NiSe₂. The optimal hydrogen evolution rate of 643.16 μmol g^?1 h^?1 is from NiSe₂/CN-5 under visible light. Superior light absorption and interfacial charge transfer properties including suppressed photogenerated carrier recombination and efficient separation of photogenerated electron-hole pairs have been observed, which account for the enhanced photocatalytic performance of CN.     

A new insight for photocatalytic hydrogen production by a Cu/Ni based cyanide bridged polymer as a co-catalyst on titania support in glycerol water mixture

A two dimensional Cu/Ni based coordination polymer [{Cu^II(4,4ʹ-dipy)₂}{Ni(CN)₄}]_n·0.7(C₂H₆O₂)·1.6(H₂O) (CP-1) (4,4ʹ-dipy = 1,3-di (4-pyridyl)propane) has been demonstrated as a potential co-catalyst on TiO₂ support for hydrogen evolution under UV light. CP-1/TiO₂ composite exhibits considerable hydrogen production in comparison with the pristine CP-1 and TiO₂ (P25), highlighting that the photocatalytic performance is significantly related with the good separation of photo generated e⁻/h⁺ pairs. Different wt. % (2.5, 5 and 7.5%) of CP-1 in CP-1/TiO₂ composites were tested for photocatalytic hydrogen production in 5 vol % glycerol/water mixture. The 5 wt % CP-1/TiO₂ composite displayed the greatest hydrogen production of 9.2 mmolh⁻¹g⁻¹. The concealed mechanism is divulged on the behalf of results obtained by cyclic voltammetry, photoluminescence and diffused reflectance/UV-visible studies which demonstrate that upon irradiation of UV light, electrons transfer from TiO₂ conduction band to CP-1. CP-1 not only grabs the conduction band electrons of titania but also performes as a co-catalyst to reduce the protons into hydrogen. These results are anticipated to direct the forthcoming advancement in creating proficient, cheap semiconductor photocatalysts for solar hydrogen production.     

Sorption of hydrogen onto titanate nanotubes decorated with a nanostructured Cd3[Fe(CN)6]2 Prussian Blue analogue

Nanostructured films of cadmium hexacyanoferrate (III), Cd₃[Fe(CN)₆]₂ have been deposited on the surface of titanate nanotubes (TiNT) by ion exchange with CdSO₄, followed by reaction with K₃[Fe(CN)₆] in an aqueous suspension. The composite demonstrates a significantly higher hydrogen storage uptake than pure Cd₃[Fe(CN)₆]₂ and TiNT. At a temperature of 77 K and a pressure 100 bar, the hydrogen uptake for the composite is approximately 12.5 wt %, whereas only 4.5 wt % and 4 wt % are achieved for the TiNT and Cd₃[Fe(CN)₆]₂ respectively. Electron microscopy and infrared spectroscopy show that Cd₃[Fe(CN)₆]₂ is uniformly distributed on the surface of the nanotubes forming a discontinuous nanostructured film with a well developed interface, which allows efficient interaction with the support. The possible reasons for the high uptake of hydrogen in the composite are discussed.     

Enhanced hydrogen production over incorporated Cu and Ni into titania photocatalyst in glycerol-based photoelectrochemical cell: Effect of total metal loading and calcination temperature

The solar driven hydrogen production was successfully investigated in a glycerol-based photoelectrochemical cell (PEC) over nanostructured TiO₂ supported bimetallic Cu and Ni by adjusting total metal loading (5, 10, and 15 mol%) and calcination temperature (400, 450, 500, and 600 °C). The effects of the mentioned parameters on physicochemical and photoelectrochemical properties of prepared Cu–Ni/TiO₂ photoanodes were explored by using different characterization techniques. The hydrogen evolution was experimentally found to be affected total metal loading and calcination temperature. The calcined photocatalyst with the total metal loading of 5 mol% at 450 °C was identified as the most efficient photocatalyst by producing maximum accumulative hydrogen of 694.84 μmol. A high performance of this photocatalyst is mainly attributed to its proper particle size and great ratio of Ti³⁺:Ti⁴⁺ and Cu⁺:Cu²⁺ in TiO₂ matrix. These better physicochemical properties enhanced charge carrier separation, which retarded the charge recombination and enhanced the transportation of photo-induced electrons at the photoelectrode/electrolyte interface. The intermediates from photooxidation of glycerol were verified using high performance liquid chromatography, indicating a partial oxidation of glycerol with selective pathway in KOH (1 M) solution. This work demonstrates that optimization Cu–Ni/TiO₂ photoanode has the practical potential in PEC cell to generate hydrogen from solar and biomass energy.     

Donor-π-acceptor dye-sensitized photoelectrochemical and photocatalytic hydrogen evolution by using Cu2WS4 co-catalyst

Photoelectrochemical and photocatalytic hydrogen evolution reaction (HER) have been investigated by using metal free donor-acceptor (D-A) and donor-π-acceptor (D-π-A) dyes, which are abbreviated as MC-32 and MC-048, respectively, sensitized TiO₂ as a photocatalyst with or without Cu₂WS₄ co-catalyst. This co-catalyst is synthesized by a low-cost and simple hot injection method, under visible light illumination. The photoactivities of these dyes have been clarified according to their structural, optical and electrochemical properties. Photocatalytic activities have been slightly increased when added the Cu₂WS₄ co-catalyst (dye/TiO₂/Cu₂WS₄). This catalytic activity is also compared to that of noble metal Pt (dye/TiO₂/Pt). It has been found that 121 μmolg⁻¹h⁻¹, 179 μmolg⁻¹h⁻¹, 348 μmolg⁻¹h⁻¹, 212 μmolg⁻¹h⁻¹, 422 μmolg⁻¹h⁻¹ and 1139 μmolg⁻¹h⁻¹ hydrogen have been evolved by using MC-32/TiO₂, MC-32/TiO₂/Cu₂WS₄, MC-32/TiO₂/Pt, MC-048/TiO₂, MC-048/TiO₂/Cu₂WS₄ and MC-048/TiO₂/Pt, respectively.     

CuO@NiO core-shell nanoparticles decorated anatase TiO2 nanospheres for enhanced photocatalytic hydrogen production

Core-shell structured co-catalyst has been created much attention in photocatalytic hydrogen production due to their efficient electron-hole pair separation, suppression of surface back reaction and long term stability. Here, we report the preparation of CuO@NiO hierarchical nanostructures as a co-catalyst deposited on TiO₂ nanospheres for enhanced photocatalytic hydrogen generation. The formation of ultrathin NiO shell over the CuO core was confirmed by TEM analysis. Fabricated core-shell nanostructured CuO@NiO over TiO₂ nanospheres was studied for hydrogen evolution under the direct solar light and it showed a high rate of H₂ production of 26.1 mmol. h⁻¹. g⁻¹_cat. It was scrutinized that the rate of hydrogen production was improved with shell thickness and co-catalyst loading. Systematic investigation on CuO@NiO co-catalyst loading, pH of the medium and glycerol concentration for augmented H₂ production. The recorded rate of hydrogen production is almost six folds greater than that of pristine TiO₂. In the view of largescale synthesis for alternative energy storage applications, the composited photocatalyst was made of by simple mixing method, which could be scaled up without any loss in photocatalytic activity. Further, the stability test of photocatalyst for continuous use found that 82% of initial photocatalytic activity is retained even after three days.     

Pt – g-C3N4 – (Au/TiO2): Electronically integrated nanocomposite for solar hydrogen generation

A potential nanocomposite photocatalyst was designed by integrating Pt nanoclusters (co-catalyst and electron sink) with graphitic carbon nitride (g-C₃N₄ (gcn)) (charge diffusion) and 0.5 wt % Au containing Au-TiO₂ (AuT) (plasmonic on semiconductor) for solar water splitting (SWS). Variety of Pt-gcn-AuTiO₂ compositions has been evaluated for SWS under one sun conditions. Complexity of the photocatalyst was increased systematically from Au-TiO₂, gcn-TiO₂ to Pt-gcn-Au-TiO₂ to explore the influence of different combinations. Electronic integration of charge separation/diffusion component (gcn) with light absorbing sensitizer components (Au and gcn), and co-catalyst (Pt) seems to be the critical factor to improve hydrogen yield (HY) or overall efficiency. Although addition of gcn increase the HY of composites, there is no SWS activity observed on bare TiO₂ or gcn. Au or Pt on gcn enhances the charge separation effectively and interface between Au and/or Pt with gcn works as the Schottky barrier. A monodispersion of Au over TiO₂ and Pt nanoclusters over gcn/AuTiO₂ composite lead to the maximum solar hydrogen yield (1.52 mmol/h g) with an apparent quantum yield (AQY) of 7.5%. Photoelectron and photoluminescence spectral studies confirm the electron transfer from Au to gcn, and Au and/or gcn to titania. A thorough physico-chemical investigation of various composites underscores the electronic integration aspects of the nanocomposite towards storage of electrons in the Pt co-catalyst and hence an effective charge separation and an increase in AQY.     

CuOCr2O3 core-shell structured co-catalysts on TiO2 for efficient photocatalytic water splitting using direct solar light

Synthesis of core-shell structured CuOCr₂O₃ nanoparticles as co-catalyst to improve the photocatalytic hydrogen evolution performance of TiO₂ was demonstrated. The effect of co-catalyst loading on TiO₂ and the nature of the reactor was found to be more significant for H₂ production under direct solar light. The formation of 9.3 nm Cr₂O₃ shell over CuO core in the CuOCr₂O₃ nanostructured co-catalyst was confirmed using transmission electron microscopy. A very high H₂ production rate of 82.39 and 70.4 mmol h^?1 g^?1_cat was observed with quartz and pyrex reactors under direct solar light of irradiation 96–100 mW/cm², respectively. This is almost three times higher than that of bare TiO₂ under similar experimental conditions. The core-shell co-catalyst loaded on TiO₂ by simple mechanical mixing method which is useful for bulk scale synthesis in practical applications. The observed high H₂ production was explained with plausible mechanism where the synergic effect of CuOCr₂O₃ co-catalyst loaded TiO₂ surface that reduces the effective charge carriers recombination and impeded backward reaction by the Cr₂O₃ thin layer. The presence of Cu²⁺ and absence of Cu⁺ and metallic Cu was confirmed using XPS analysis. The effect of co-catalyst loading and sacrificial agent concentration on the photocatalytic hydrogen production was also reported. The stability of the CuOCr₂O₃ core-shell NPs loaded TiO₂ photocatalyst under the direct solar light was examined by continuous cycling for three days and it was found to be 81 and 70% of photocatalyst activity is retained after 3 days in the quartz and pyrex reactor systems, respectively.     

Highly efficient photocatalytic hydrogen evolution by using Rh as co-catalyst in the Cu/TiO2 system

Cu/TiO₂ was modified by adding Rh as co-catalyst and used as a highly efficient photocatalyst for the hydrogen evolution reaction. A low amount of Rh was loaded onto Cu/TiO₂ by the deposition-precipitation with urea (DPU) method to observe the effect on the hydrogen production displayed by different samples. The Rh–Cu/TiO₂ oxide structure exhibited a remarkably high photocatalytic hydrogen evolution performance, which was about twofold higher than that of the Cu/TiO₂ monometallic photocatalyst. This outstanding performance was due to the efficient charge carrier transfer as well as to the delayed electron-hole recombination rate caused by the addition of Rh. The influence of the different parameters of the photocatalyst synthesis and reaction conditions on the photocatalytic activity was investigated in detail. Hydrogen evolution was studied using methanol, ethanol, 2-propanol and butanol as scavengers with an alcohol:water ratio of 20:80. The methanol-water system, which showed the highest hydrogen production, was studied under 254, 365 and 450 nm irradiation; Rh–Cu/TiO₂ showed high photocatalytic activity with H₂ production rates of 9260, 5500, and 1940 μmol h^?1 g^?1, respectively. The Cu–Rh/TiO₂ photocatalyst was active under visible light irritation due to its strong light absorption in the visible region, low band gap value and ability to reduce the electron (e^?) and hole (h⁺) recombination.     

Manipulating photocatalytic pathway and activity of ternary Cu2O/(001)TiO2@Ti3C2Tx catalysts for H2 evolution: Effect of surface coverage

A Cu₂O/(001)TiO₂@Ti₃C₂T_x photocatalyst was synthesized via a wet-chemistry reduction method by N, N-dimethylformamide (DMF). By scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), and X-ray diffraction (XRD), it was revealed that the surface coverage of photocatalyst increased with the loading amount of Cu₂O, while the particle size of Cu₂O did not change significantly. The photocatalytic activity and mechanism of ternary Cu₂O/(001)TiO₂@Ti₃C₂T_x photocatalyst heavily depend on the surface coverage of copper species. When the surface coverage of photocatalyst by Cu₂O was low, the Ti₃C₂T_x acted as hole reservoir. Cu₂O was firstly reduced in situ to metallic copper by excited electrons. Then the reverse movement of carriers enabled the spatial separation of photogenerated electron-hole pairs, and afforded relatively high hydrogen evolution (more than 1100 μmol h⁻¹ (g CuO_x TiO₂)⁻¹). When the coverage of Cu₂O on (001)TiO₂@Ti₃C₂T_x was too high at high loading amounts, Ti₃C₂T_x failed to play the role of hole trapping. Under that circumstance, the photocatalytic reaction follows p-n junction mechanism, leading to low hydrogen productivity. The results here shed light on the relationship between structure and activity of Cu₂O/(001)TiO₂@Ti₃C₂T_x, which was conducive to the development of the MXene-based photocatalysts.     

g-C3N4 doping TiO2 recovered from spent catalyst for H2 evolution from water

Spent catalysts of selective catalytic reduction (SCR) contain a high content of TiO₂ (>70 wt%). The effective recovery of TiO₂ from spent SCR catalysts and its reuse in photocatalytic hydrogen production is of great importance for environmental protection. In this study, the recovered TiO₂ from the spent SCR catalyst was recovered by the alkali washing method, and the purity of the recovered TiO₂ reached 94.7%. g-C₃N₄ as a co-catalyst and enhanced the separation efficiency of the photogenerated electron-hole pairs of the TiO₂ photocatalyst. The composite photocatalyst R–TiO₂/g-C₃N₄ prepared by directly mixing the recovered TiO₂ with g-C₃N₄ significantly improved the photocatalytic activity. The experimental design of the photocatalyst synthesis was optimized using the Design Expert software. The results showed that the recovered TiO₂ was 0.334 g when the g-C₃N₄ was 0.046 g and the ultrasonic time was 163 min. Moreover, the hydrogen production rate reached 443.105 μmol g⁻¹ h⁻¹ within 4 h.     

Kinetic performance of TiO2/Pt/reduced graphene oxide composites in the photocatalytic hydrogen production

Among the different alternatives to generate hydrogen, photocatalysis can play an important role since it is based on the use of solar radiation and a suitable semiconductor. Starting from the most commonly researched TiO₂ catalyst, many efforts have been devoted to improve its efficacy. This work, based on the potential of reduced graphene oxide (rGO) to carry charges and platinum nanoparticles to act as efficient traps for photogenerated electrons, assesses the performance of synthesized binary and ternary photocatalysts (TiO₂/rGO, TiO₂/Pt and TiO₂/rGO/Pt) for hydrogen generation. The addition of rGO to TiO₂ almost duplicates (1.95 factor) the hydrogen production rate compared to bare TiO₂. Moreover, the binary TiO₂/Pt photocatalyst reported the best performance, with an increase in the hydrogen production rate by a factor of 15.26 compared to TiO₂. However, the ternary catalyst performed worse than the binary TiO₂/Pt probably due to the use of non-optimized co-catalyst ratios. Since the addition of rGO reduces the cost of the catalyst, the trade-off between the catalyst performance and cost is worth of future research.     

CoNi bimetallic alloy cocatalyst-modified TiO2 nanoflowers with enhanced photocatalytic hydrogen evolution

In terms of improving photocatalytic hydrogen production performance, inexpensive and earth-rich cocatalysts have become promising alternatives to precious metals. Herein, a novel CoNi–TiO₂ photocatalyst composed of TiO₂ nanoflowers and CoNi alloy was prepared by hydrothermal and chemical reduction methods. Various characterizations and test results have confirmed that the further improvement of the photocatalytic performance of the CoNi–TiO₂ photocatalyst is mainly due to the fact that the bimetallic CoNi alloy can accelerate charge transfer and inhibit the recombination of photo-induced carriers. The hydrogen production rate of the prepared CoNi–TiO₂ is about 24 times higher than that of the pristine TiO₂, and its hydrogen production rate value can reach 6580.9 μmol g^?1 h^?1, and showing comparable photocatalytic performance to 0.5 wt% Pt–TiO₂. In addition, combined with the characterization results, a probable mechanism for enhanced photocatalytic performance was proposed. This study provides favorable enlightenment for the design of a series of highly efficient non-precious metal TiO₂-based photocatalysts.     

New insights in the performance and reuse of rGO/TiO2 composites for the photocatalytic hydrogen production

The viability of the photocatalytic hydrogen production is closely related to the performance and long term stability of the photocatalyst. In this work rGO/TiO₂ composites have been synthetized with graphene oxide (GO) ratios from 1% to 10% and experimentally assessed towards hydrogen generation from methanol solutions. The performance of the composite with 2% of rGO (2 GT) has been compared to bare TiO₂ working with 20% volume methanol solution. The hydrogen production initial rate showed similar values with both photocatalysts decreasing after about 24 h. Further analysis of the photocatalytic process at longer times showed the negative influence of hydrogen accumulation in the reaction system. Thus, an experimental procedure with argon purge was developed and the behavior of TiO₂ and 2 GT photocatalysts was compared. It is concluded that TiO₂ keeps its activity after 8 operation cycles while 2 GT performance reduces progressively. This can be attributed to the further reduction of GO and the increase of defects in its structure.     

Synthesis of g-C3N4/TiO2 with enhanced photocatalytic activity for H2 evolution by a simple method

A photocatalyst composed of graphite-like carbon nitride (g-C₃N₄) and TiO₂ was fabricated by a simple method to calcine the mixture of melamine and TiO₂ precursor. The photocatalyst has enhanced photoactivity for hydrogen evolution from water. Characterization by XRD, FTIR, SEM and elemental analysis showed that the crystal structure and morphologies of composites were affected by the amount of melamine in the composite. The UV–Vis characterization displayed that the optical absorption range of g-C₃N₄/TiO₂ hybrid was broadened with a synergistic effect. The photoactivity for H₂ evolution was shown that the best result obtained from the composite with 67 wt% melamine has about 5 times improvement compared with bare TiO₂ or pure g-C₃N₄. The enhanced photoactivity might be related with the favorable structure resulted from heat-treatment temperature, and the content of g-C₃N₄ participating in wide optical absorption, separation and transportation of electronic-holes, as well as morphology of composite.     

In situ tuning of band gap of Sn doped composite for sustained photocatalytic hydrogen generation under visible light irradiation

The significance of Sn dopant on the photocatalytic performance of Iron/Titanium nanocomposite towards photocatalytic hydrogen generation by water splitting reaction is investigated. Iron/Titanium nanocomposite modified by Sn⁴⁺ dopant acts as a suitable photocatalyst for induced visible light absorption facilitating pronounced charge separation efficiency. Various characterization techniques reveal the heterojunction formation of hematite Fe₂O₃ with anatase - rutile mixed phase of TiO₂ employing Sn doping, where Sn⁴⁺ dopant accomplishes the phase transformation of anatase to rutile, entering into the TiO₂ lattice. This extended the lifetime of photogenerated charge carriers and enhanced the quantum efficiency of the photocatalyst. The band gap of the nanocomposite is tuned to ~2.4 eV, favoring visible light absorption. A hydrogen generation activity of 1102.8 μmol, approximately five times higher than the lone system (216.5 μmol) is achieved for the 5% Sn doped system for an average of 5 h. Heterojunctions of hematite with anatase-rutile mixed phase, generated as a consequence of tin doping facilitated the enhanced hydrogen generation activity of photocatalyst.     

Highly efficient thiomolybdate [Mo2S12]2- nanocluster cocatalyst decorated on TiO2 to boost photocatalytic hydrogen evolution

The exploitation of noble-metal-free photocatalysts with high solar-to-H₂ conversion efficiency is a hot topic in the photocatalysis field. Molybdenum sulfide materials, which have good physicochemical properties and excellent hydrogen evolution activity, have become an effective noble metal cocatalyst substitute and attracted widespread attention. In this work, a highly efficient photocatalyst constructed by decorating thiomolybdate [Mo₂S₁₂]^2- nanoclusters on TiO₂ is reported for the first time. The resultant [Mo₂S₁₂]^2-/TiO₂ photocatalyst shows a remarkable enhanced hydrogen evolution rate under the Xenon light irradiation. At the optimal loading amount of [Mo₂S₁₂]^2-, the photocatalyst exhibits a photocatalytic hydrogen evolution rate of 213.1 μmol h^?1 g^?1, which is about 51 times that of the pure TiO₂. Characterization results show that the intimate contact between [Mo₂S₁₂]^2- and TiO₂ promotes the separation of hole-electron pairs, prolongs the lifetime of carriers, and thereby increases the photocatalytic activity. Furthermore, abundant bridging S in the [Mo₂S₁₂]^2- acts as active sites for hydrogen evolution, which also contributes to the enhanced hydrogen production rate. This work demonstrates an efficient way for the construction of noble-metal-free hydrogen evolution photocatalyst and provides a useful reference for the development of low cost photocatalysts in the future.     

One-pot synthesis of Cu–TiO2/CuO nanocomposite: Application to photocatalysis for enhanced H2 production,dye degradation & detoxification of Cr (VI)

Photocatalytic hydrogen production under the visible spectrum of solar light is an important topic of research. To achieve the targeted visible light hydrogen production and improve the charge carrier utilization, bandgap engineering and surface modification of the photocatalyst plays a vital role. Present work reports the one-pot synthesis of Cu–TiO₂/CuO nanocomposite photocatalyst using green surfactant -aided -ultrasonication method. The materials characterization data reveals the TiO₂ particle size of 20–25 nm and the existence of copper in the lattice as well as in the surface of anatase TiO₂. This is expected to facilitate better optical and surface properties. The optimized photocatalyst shows enhanced H₂ production rate of 10,453 μmol h⁻¹ g⁻¹ of the catalyst which is 21 fold higher than pure TiO₂ nanoparticles. The photocatalyst was tested for degradation of methylene blue dye (90% in 4 h) in aqueous solution and photocatalytic reduction of toxic Cr⁶⁺ ions (55% in 4 h) in aqueous solution. A plausible mechanistic pathway is also proposed.     

Facile synthesis of anatase/rutile TiO2/g-C3N4 multi-heterostructure for efficient photocatalytic overall water splitting

Rational design of high-efficiency heterostructure photocatalyst is an effective strategy to realize photocatalytic H₂ evolution from pure water, but remains still a considerable challenge. Herein, an anatase/rutile TiO₂/g-C₃N₄ (A/R/CN) multi-heterostructure photocatalyst was prepared by a facile thermoset hybrid method. The combination of two type-II semiconductor heterostructures (i.e., A/R and R/CN) significantly improve the separation and transfer efficiency of photogenerated carriers of anatase TiO₂, rutile TiO₂ and g-C₃N₄, and A/R/CN photocatalyst with high activity is obtained. The optimal A/R/CN photocatalyst exhibits significantly increased photocatalytic overall water splitting activity with a rate of H₂ evolution of 374.2 μmol g⁻¹h⁻¹, which is about 8 and 4 times that of pure g-C₃N₄ and P25. Moreover, it is demonstrated to be stable and retained a high activity (ca. 91.2%) after the fourth recycling experiment. This work comes up with an innovative perspective on the construction of multi-heterostructure interfaces to improve the overall photocatalytic water splitting performance.     

Unexpected facilitation of the pyrolysis products of potassium ferrocyanide to the electrocatalytic activity of a PdO based palladium iron composite catalyst towards ethanol oxidation reaction (EOR)

It was found, for the first time, that the pyrolysis products of potassium ferrocyanide (K₄[Fe(CN)₆]) could significantly promote the electrocatalytic activity of the PdO based palladium iron composite catalyst towards ethanol oxidation reaction (EOR). In this work, huge carbon spheres (abbreviated as HCSs) were prepared firstly via a pyrolysis method using glucose and 1-butyl-3-methylimidazolium tetrafluoroborate as the starting materials. Secondly, PdO based palladium iron composites supported on HCSs (noted as PdO–Pd–Fe/HCSs) were successfully fabricated through a pyrolysis procedure employing PdO·H₂O, HCSs and K₄[Fe(CN)₆] as the initial materials. When preparing PdO–Pd–Fe/HCSs, four different amounts of K₄[Fe(CN)₆] were respectively added in the preparation system producing four kinds of samples. The sample prepared in the absence of K₄[Fe(CN)₆] was nominated as sample b-0. And the samples prepared in the presence of 5, 10 and 20 mg K₄[Fe(CN)₆] were, respectively, labeled as sample b-5, b-10 and b-20. It was indicated by the XRD and XPS patterns that the metallic Pd particles were the main crystalline materials of above four samples. SEM images of all synthesized samples substantially demonstrated that the added amount of K₄[Fe(CN)₆] was a pivotal factor which could significantly affect the morphologies of the prepared samples. For sample b-0, besides some nanoparticles with a size close to 30 nm, a larger number of pores were created on the surface of the HCSs producing a honeycomb-shaped surface. Interestingly, aniseed shaped particles, cauliflower-like particles and irregular particles with a diameter more than 150 nm were, respectively, anchored on the HCSs surface of sample b-5, b-10 and b-20. Most of all, as indicated by CV and CA measurements, all the samples prepared in the presence of K₄[Fe(CN)₆] delivered much better electrocatalytic activities towards EOR when compared to the sample prepared with no addition of K₄[Fe(CN)₆]. For example, in the CV curves, the peak current density of the peak appearing in the positive potential scanning (peak f) for EOR on sample b-10 was nearly 6.4 times greater than that on sample b-0 (16.6 mA cm^?2 vs. 2.6 mA cm^?2). The significantly decreased charge transfer resistance and the remarkably enlarged electrochemical surface area were analyzed to be the main reasons for sample b-10 to exhibit the best electrocatalytic performance among all prepared samples. In general, a novel electrocatalyst consisting of PdO, Pd and the pyrolysis products of K₄[Fe(CN)₆] for EOR was developed in this work, which, due to its very lower preparation cost and its satisfied electrocatalytic activity towards EOR, was very helpful to the development of Pd-based EOR electrocatalyst.