Photochemical Water Splitting Research Articles

Photoelectrochemical Water Splitting: A Visible-Light-Driven CoTiO3@g-C3N4-Based Photoanode Interface Follows the Type II Heterojunction Scheme.

Harnessing solar energy can be efficiently used to generate hydrogen by photochemical water splitting, which is a sustainable and environmentally benign energy source. Here, a unique visible-light-driven CoTiO3@g-C3N4 (CTOCN)-based photoanode interface has been optimized and developed with modification to follow the type II heterojunction for the enhancement of photoelectrochemical water splitting. Initially, a graphitic carbon nitride-loaded CoTiO3 (with 10 wt % g-C3N4) composite was obtained using a one-pot solvothermal method. Accordingly, the type II heterojunction interface between g-C3N4 and CoTiO3 has been successfully created and confirmed by the acquired phase, morphological, and optical examinations. Thereby, heterostructure generations with interfacial interaction were enabled to decrease photogenerated electron-hole pair recombination, leading to enhanced charge transfer for water oxidation kinetics. The minimal charge transfer resistance and hole relaxation lifetime (p) shown in Nyquist and Bode plots have further confirmed the rapid electron transport across the electrode/electrolyte interfaces, which is attributed to an enhanced absorption of holes for the water splitting process. Additionally, UV-vis spectroscopy, Mott-Schottky analysis, and UPS studies were used to determine the band edge locations of g-C3N4 and CoTiO3. In comparison to previously developed nanohybrids and their equivalents, the CTOCN-d photoanode follows the type II charge transfer mechanism, resulting in a higher photocurrent density of 55.51 mA cm-2.

Aluminum Oxide Nanoparticles as a Photocatalyst for Water Splitting

Among various photoinduced hydrogen gas production techniques, photochemical catalytic water splitting is promising and an ideal future energy source because of the low cost, stability, and high sustainability of the reaction system features. Aluminum oxide nanoparticles (Al2O3NPs) as a photocatalyst for the splitting of water into hydrogen gas using solar energy is one of the noble missions of material science. In this work, pure aluminum oxide and L-methionine-capped aluminum oxide NPs have been synthesized using the sol-gel method. The pure Al2O3 and capped Al2O3 NPs with L-methionine were investigated by Fourier transform infrared (FTIR), X-ray diffractometer (XRD), high-resolution transmission electron microscopy (HRTEM), and Zeta potential. It was found that the average particle sizes of Al2O3 NPs and capped Al2O3 NPs with L-methionine were 13 and 20 nm, respectively. L-methionine-capped Al2O3 NPs had a higher negative charge with a potential of - 24.5 mV. The capping agent slightly improved the production of hydrogen from 44 to 60 ml at 75° C after 30 min under illumination.

Photochemical water splitting via transition metal complexes

Photochemical water splitting by transition metal complexes provides a new approach to the production of hydrogen as a clean and sustainable energy carrier. Several selected systems are analyzed, and the two basic half reactions in the water splitting process which generates hydrogen and the compound of water oxidation (oxygen or hydrogen peroxide) are presented. Finally, a system designed for photochemical water splitting, based on the radical and organometallic chemistry of titanocene(III), is postulated.

Insights of water-to-hydrogen conversion from thermodynamics

<p>Water-to-hydrogen can be achieved using a variety of driving energy sources, including thermal, electrical, or photo energy. While methods for hydrogen production in specific energy driving scenarios have been extensively studied, a comprehensive theory to explain the conversion of various energies into hydrogen is still lacking. This study provides a novel exergy-based perspective on hydrogen production methods, revealing that the thermodynamic infeasible water splitting process is derived from insufficient exergy input relative to the reaction exergy requirement. Enhancing the exergy input beyond the reaction exergy requirement can break through chemical equilibrium and enable the reaction to proceed. Providing high exergy-to-energy ratios of energy sources such as electrical, photo, and chemical energy for thermochemical water splitting reactions can reduce the thermal exergy demand for hydrogen production, thus facilitating water-to-hydrogen conversion at lower temperatures. By applying this new insight to coupled photochemical- and thermochemical water splitting reactions, equilibrium conversion rates corresponding to solar spectra with different wavelengths are obtained. The highest water-to-hydrogen conversion rate is achieved by the solar spectrum at a wavelength of about 451nm. The appropriate wavelength region for high water-to-hydrogen conversion is identified. This study also identifies the theoretical conversion limit of photochemical water splitting, providing insights into the potential improvements of current experiments. More importantly, our work offers a unified thermodynamic framework for understanding hydrogen production methods and presents a theoretical basis for reducing reaction temperature and enhancing conversion rate.</p>

Symbiotic MoO3-SrTiO3 Heterostructured Nanocatalysts for Sustainable Hydrogen Energy: Combined Experimental and Theoretical Simulations.

Highly efficient Z-scheme MoO3-SrTiO3 heterostructured nanocatalytic systems were engineered via a sol-gel chemical route and exploited in green H2 energy synthesis via overall water splitting. The optical and electronic investigations corroborated the enhancement of the optoelectronic properties of SrTiO3 after the incorporation of MoO3. Emergence of the interfacial charge transfer between SrTiO3 and MoO3 is the driving force, which synergistically triggered the catalytic efficiency of MoO3-SrTiO3 heterostructures. The substitution of Ti4+ by Mo6+ ions led to the suppression of Ti3+ mid-gap states, as the potential involved in the Mo6+/Mo5+ reduction is higher than that in Ti4+/Ti3+. Theoretical studies were employed in order to comprehend the mechanism behind the advancement in the catalytic activity of MoO3-SrTiO3 porous heterostructures, which also possessed a higher surface area. 2% MoO3-SrTiO3 exhibited the optimum catalytic response toward H2 evolution via photochemical, electrochemical, and photo-electrochemical water splitting. 2% MoO3-SrTiO3 evolved H2 at the fourfold higher rate than SrTiO3 with phenomenal 16.06% AQY during photochemical water splitting and photo-degraded MB dye at nearly 88% against the 42% degradation in SrTiO3-led photocatalysis. Electrochemical and photo-electrochemical investigations also manifested the superiority of 2% MoO3-SrTiO3 toward HER, as it exhibited accelerated current and photocurrent densities of 25.02 and 27.45 mA/cm2, respectively, at the 1 V potential. EIS studies demonstrated the improved charge separation efficiency of MoO3-SrTiO3 heterostructures. This work highlights the multi-dimensional approach of obtaining green H2 energy as the sustainable energy source using MoO3@SrTiO3 heterostructures.

Tuning assembly of Ni-doped Au@FexOy magnetoplasmonic nanowires for optimizing photochemical water splitting

The design of the particular geometric electrodes in photo-electrocatalysis is of significant importance to directly influence their catalytic performance. In this study, we have synthesized Ni-doped Au@FexOy magnetoplasmonic nanowires (MagPlas NWs) and leveraged diverse orientations of magnetic flux to disclose the active surfaces of the nanowire arrays incorporated into the electrode framework, thereby bringing to light active surface areas that facilitate adsorption of photons. Subjecting the Ni-Au@FexOy MagPlas NWs to magnetic fields at various orientations affects their light absorption intensity. The transverse mode exhibits impressive visible light absorption, which significantly increases its photocatalytic performance in oxygen evolution reaction (OER). The rugged forest shape array possesses remarkable visible light absorption, enhanced 2.01 mA cm−2 at 1.23 V vs. a reference hydrogen electrode (RHE), and long-term stability. The enhanced photoactivity is attributed to higher specific surface porosity and tuning of the magnetic field orientation to modulate the absorbance properties of the NWs.

Single-Particle Measurements Reveal the Origin of Low Solar-to-Hydrogen Efficiency of Rh-Doped SrTiO3 Photocatalysts.

Solar-powered photochemical water splitting using suspensions of photocatalyst nanoparticles is an attractive route for economical production of green hydrogen. SrTiO3-based photocatalysts have been intensely investigated due to their stability and recently demonstrated near-100% external quantum yield (EQY) for water splitting using wavelengths below 360 nm. To extend the optical absorption into the visible, SrTiO3 nanoparticles have been doped with various transition metals. Here we demonstrate that doping SrTiO3 nanoparticles with 1% Rh introduces midgap acceptor states which reduce the free electron concentration by 5 orders of magnitude, dramatically reducing built-in potentials which could otherwise separate electron-hole (e-h) pairs. Rhodium states also function as recombination centers, reducing the photocarrier lifetime by nearly 2 orders of magnitude and the maximum achievable EQY to 10%. Furthermore, the absence of built-in electric fields within Rh-doped SrTiO3 nanoparticles suggests that modest e-h separation can be achieved by exploiting a difference in mobility between electrons and holes.

Enhanced hydrogen generation via overall water splitting using novel MoS2-BN nanoflowers assembled TiO2 ternary heterostructures

Envisaging headway in the applicability of sustainable H2 energy, the novel report of the fabrication of MoS2-BN/TiO2 (MBT) heterogeneous nanostructures has been proposed via facile in-situ hydrothermal route with an aim to propound the superior substitute of noble metal based conventionally employed catalytic system to surmount their exorbitant cost. We inferred the ascendancy of MoS2-BN nanoflowers over pristine MoS2 counterpart in an establishment of TiO2 based heterostructured catalysis. MBT heterostrucutres were extensively scrutinized with respect to their structural, optoelectronic and computational characteristics. En route to enhanced H2 evolution, we have investigated the significance of interfacial junctions and exposed sites in the MBT heterostructures. In order to achieve broader pertinence in green H2 fuel, the performance of MBT heterostrucutres was ascertained with subject to photochemical, electrochemical and photo-electrochemical (PEC) water splitting. Loaded concentration of MoS2-BN was varied in MBT catalysts and 2.5 wt% MoS2-BN/TiO2 exhibited optimum photocatalytic response with an H2 production rate of 2.6 mmol/g/h with 6.94% AQY and improved photo-current response of 0.99 mA/cm2 towards PEC. Electrochemical investigations further intensified the caliber of MBT as HER catalyst ascribed to the higher cathodic current density of 49.23 mA/cm2 at 1.22 V potential. The advancement in the catalytic efficiency of MBT heterostructures was evidenced by the synergetic relationship between MoS2-BN and TiO2 which stimulated the separation and transfer of photo-charged carriers, and lowered the overpotential values consequently surging the kinetics of H2 evolution.

Rhenium-Based Electrocatalysts for Water Splitting

Due to the contamination and global warming problems, it is necessary to search for alternative environmentally friendly energy sources. In this area, hydrogen is a promising alternative. Hydrogen is even more promising, when it is obtained through water electrolysis operated with renewable energy sources. Among the possible devices to perform electrolysis, proton exchange membrane (PEM) electrolyzers appear as the most promising commercial systems for hydrogen production in the coming years. However, their massification is affected by the noble metals used as electrocatalysts in their electrodes, with high commercial value: Pt at the cathode where the hydrogen evolution reaction occurs (HER) and Ru/Ir at the anode where the oxygen evolution reaction (OER) happens. Therefore, to take full advantage of the PEM technology for green H2 production and build up a mature PEM market, it is imperative to search for more abundant, cheaper, and stable catalysts, reaching the highest possible activities at the lowest overpotential with the longest stability under the harsh acidic conditions of a PEM. In the search for new electrocatalysts and considering the predictions of a Trasatti volcano plot, rhenium appears to be a promising candidate for HER in acidic media. At the same time, recent studies provide evidence of its potential as an OER catalyst. However, some of these reports have focused on chemical and photochemical water splitting and have not always considered acidic media. This review summarizes rhenium-based electrocatalysts for water splitting under acidic conditions: i.e., potential candidates as cathode materials. In the various sections, we review the mechanism concepts of electrocatalysis, evaluation methods, and the different rhenium-based materials applied for the HER in acidic media. As rhenium is less common for the OER, we included a section about its use in chemical and photochemical water oxidation and as an electrocatalyst under basic conditions. Finally, concluding remarks and perspectives are given about rhenium for water splitting.

The influence of trinuclear complexes on light-induced hydrogen production

New trinuclear water reduction catalysts show turnover numbers for photochemical water splitting of up to 8899, a turnover frequency of 2737 h−1 and an incident photon conversion efficiency of 2.1%, thus outperforming mononuclear analogues.

Ab initio high-throughput screening of transition metal double chalcogenide monolayers as highly efficient bifunctional catalysts for photochemical and photoelectrochemical water splitting

Developing efficient bifunctional photocatalysts that can directly split water into hydrogen and oxygen driven by sunlight has attracted great attention because photocatalytic water splitting is a promising clean technology to harvest solar energy.

Analysis of photon-driven solar-to-hydrogen production methods in the Netherlands

Hydrogen is deemed necessary for the realization of a sustainable society, especially when renewable energy is used to generate hydrogen. As most of the photon-driven hydrogen production methods are not commercially available yet, this study has investigated the techno-economic and overall performance of four different solar-to-hydrogen methods and photovoltaics-based electrolysis methods in the Netherlands. It was found that the photovoltaics-based electrolysis is the cheapest option with production cost of 9.31 $/kgH2. Production cost based on photo-catalytic water splitting, direct bio-photolysis, and photoelectrochemical water splitting are found to be 18.32 $/kgH2, 18.45 $/kgH2, and 18.98 $/kgH2, respectively. These costs are expected to drop significantly in the future. Direct bio-photolysis (potential cost of 3.10 $/kgH2) and photo-catalytic water splitting (3.12 $/kgH2) may become cheaper than photovoltaics-based electrolysis. Based on preferences of three fictional technology investors, i.e. a short-term, a green and a visionary investor, the overall performance of these methods are determined. Photovoltaics-based electrolysis is the most ideal option, with photoelectrochemical water splitting a complementary option. While photovoltaics-based electrolysis has an advantage on the short-term because it is a non-integrated energy system, on the long-term this might lead to relatively higher cost and performance limitations. Photochemical water splitting are integrated energy systems and have an advantage on the long-term because they need a relatively low theoretical overpotential and benefit from increasing temperatures. Both methods show performance improvements by the use of quantum dots. Bio-photolysis can be self-sustaining and can use wastewater to produce hydrogen but sudden temperature changes could lead to performance decrease.

Strategy to utilize amorphous phase of semiconductor toward excellent and reliable photochemical water splitting performance: Roles of interface dipole moment and reaction parallelization

The roles of amorphous phases in photochemical water splitting of semiconductors are still in debate, as the effects of the amorphous phase are largely irregular even in a single material. We presumed that the photochemistry of crystal-amorphous mixed semiconductor systems would be governed by the interface characteristics, and conducted a systematic study to understand the origins of the largely varying photochemical reaction of semiconductors having an amorphous phase. First-principles calculations on crystalline anatase and amorphous TiO2 showed that the coexistence of crystalline and amorphous TiO2 and the exposure of the phase boundary are advantageous due to the accelerated charge separation by interface dipole moment and the parallelizable oxygen evolution reaction at the boundary. Our computation-based strategies were demonstrated in our experiments: only the TiO2 nanoparticle and nanotube having partial amorphization on surfaces have highly enhanced photocatalytic water splitting performances (approximately 700%) compared to the pristine and completely amorphized TiO2 systems.

Promoting highly dispersed Co3O4 nanoparticles onto polyethyne unraveling the catalytic mechanism with stable catalytic activity for oxygen evolution reaction: From fundamentals to applications

The solution to overcome the energy crisis in the globe with saving the environment from pollution and the community health, along with other applications of electrochemical for water splitting to get hydrogen and oxygen as a clean fuel. Likewise, the conducting polymers experience as stability over long time, or some time the breaking of conducting polymer chain is unavoidable with addition of polymer. For many reasons, we use noble metal co-catalysts in conjunction with semiconductors for improved hydrogen and oxygen gas production by the water splitting. The morphological characterization, & chemical composition of pristine & composite material studies with the help of different analytical techniques as like SEM, EDX, XRD, XPS & HRTEM. An outperform and active non-noble electrocatalyst for the oxygen evolution reaction which is a hotspot in the current research activities for oxygen & hydrogen production with zero carbon dioxide emission. Herein, we present an advanced material Co3O4/polyethyne for the first time to produce oxygen at a reasonable overpotential. The best oxygen evolution performance of Co3O4/polyethyne (20) providing the best performance at low overpotential 260 mV at 10 mAcm−2 the Tafel slope 64 mVdec−1, further strongly acceptable durability approximately for the 30 h & finally obtained charge transfer resistance value of 82.58 Ohms & greater capacitance 1.56 mF value for Co3O4. The key element in the success of newly developed catalyst is the greater amount of Co3O4 nanoparticles due to selective growth on polyethyne which has played a dominant role in oxygen production. It is because of the worth mentioning properties of polyethyne as a good electrical conductor, as efficient catalyst Co3O4 with more surface roughness and high surface area, which is strongly boosting the production of oxygen. The developed material can be applied in other competing fields such as lithium-ion batteries, solar cells, energy storage devices, and photochemical water splitting.

The role of current and emerging technologies in meeting Japan’s mid- to long-term carbon reduction goals

Using Japan as a proxy for a developed nation, we investigated the role of existing and nascent technologies in curbing carbon emissions. We simulated possible pathways to meeting 2030 and 2050 emission targets within the Japanese electricity supply sector using a single-region model in The Integrated MARKAL-EFOM System (TIMES). Critically, our simulations incorporate novel technologies like hydrogen electrolysers, carbon capture, photochemical water splitting, and emerging photovoltaic cells, assess long-term impacts up to the year 2100, and include life-cycle emissions and learning curves for parameters such as investment cost, efficiency, and emission coefficients. Results indicate that a hybrid approach, using nuclear power and hydrogen from renewable energy-based electrolysis, is cost-effective and provides long-term emission reduction along with energy security. Nuclear, wind, solar, and hydrogen from renewables emerge as key emission reduction technologies, while natural gas with carbon capture plays a minor role in achieving emission reduction targets.

Advances in engineering perovskite oxides for photochemical and photoelectrochemical water splitting

Solar-driven water splitting is an efficient process for converting solar energy into chemical energy. In this process, semiconductor materials are excited by solar energy to generate free electrons to participate in the water-splitting reaction. Among these semiconductor materials, inorganic perovskite oxides have a spatial structure that is easy to control and thereby lead to different energy band structures and photocatalytic properties. More importantly, perovskite oxides can be compounded with other organic/inorganic materials to promote charge separation and improve apparent quantum yield. However, the low solar-to-hydrogen conversion efficiency has not yet reached the requirements of practical applications. In this review, the fundamental principles of solar-driven water splitting based on perovskite materials are introduced according to the most recently published results. In addition, the innovative modification techniques for water splitting based on perovskite oxides have been summarized, focusing on the following methods: element doping, homo/heterojunction formation, Z-scheme, plasmon effect, dye sensitization, carbon enhancement, and surface modifications. Note that the applications in the visible light wavelength range have been described, with emphasis among all these modification materials. Furthermore, the recent water-splitting reaction systems for practical applications are briefly discussed. As a summary, we outline the challenges and potential utilization associated with visible light–driven water splitting based on perovskite oxides for future commercial applications. This review describes various modification methods to improve photochemical performance of perovskite oxides as well as illustrates the potential to employ perovskite oxides as a key material for the practical application of water splitting.

Supported polyoxometalates as emerging nanohybrid materials for photochemical and photoelectrochemical water splitting

Abstract Sunlight and water are among the most plentiful and sustainable resources of energy. Natural photosystem II in the plants uses these resources in ecofriendly manner for the production of atmospheric oxygen and energy. Inspired by this natural process, the development of artificial catalytic system to facilitate the solar-induced water splitting for the continuous production of hydrogen is the holy grail of the chemist and energy experts to meet the future energy demand at minimal environmental cost. Despite considerable research efforts dedicated to this area in the last decade, the development of highly efficient, stable and economic photocatalysts remain a challenging task for the large scale H2 production from water. Polyoxometalates (POMs)-based materials are emerging photo/photoelectrocatalysts in this quest owing to their multi-electron redox potential and fast reversible charge transfer properties, which are the essential requirements of photo-assisted water splitting catalysis. They are generally soluble in aqueous medium and thus their inherent catalytic/co-catalytic properties can be better exploited by incorporating/immobilizing them over suitable support materials. Therefore, exploration of discrete POM units over the support materials possessing high surface area, functionalizable architecture, flexible pore size and good light harvesting ability is an attractive area of research that has resulted in the generation of a strong library of heterocatalysts. The underlying support not only offers stability and recyclability attributes to the POM units but also provides decent dispersion, easy/maximum accessibility to the active sites, enhanced absorption capability, and synergistically enhances the activity by transfer of electrons and efficient charge/carriers separation by creating POM-support junctions. This mini-review emphasizes on the strategies for the incorporation of POMs on various porous supports like metal-organic frameworks (MOFs), covalent-organic frameworks (COFs), oxide-based semiconductors, carbonaceous materials, etc., and their applications as effective photo/photoelectrocatalysts for water splitting. In addition, the mechanistic study, comparative analysis and the future potential of these novel nanoscale materials is also highlighted. We believe that this review article will provide a new direction and scientific interest at the boundary of materials engineering, and solar-driven chemistry for the sustainable energy conversion/storage processes.

Multifunctionality exploration of NiCo2O4-rGO nanocomposites: photochemical water oxidation, methanol electro-oxidation and asymmetric supercapacitor applications.

Different weight percentages of NiCo2O4-rGO nanocomposites were prepared via a facile hydrothermal method. The prepared nanocomposites were structurally and morphologically characterized by X-ray diffraction, Raman spectroscopy, and electron microscopy. The structural studies show the formation of rGO-NiCo2O4 nanocomposites by embedment of porous NiCo2O4 rods on rGO sheets. The effect of the NiCo2O4 content on photochemical water oxidation was investigated. It revealed that the catalysts NiCo2O4-rGO with 1 : 26 ratio (NCO26) and 1 : 13 ratio (NCO13) are efficient in generating oxygen under light illumination. It proves that NCO26 works far more effectively as a photocatalyst compared to NCO13. Methanol electro-oxidation of the NCO26 nanocomposite shows a current density of 24 mA cm-2 at a potential of 0.45 V in cyclic voltammetry and maintains the current for 3600 s at 0.45 V in chronoamperometry. An onset potential of 0.344 V was observed for 0.5 M methanol oxidation. The specific capacitance values were found to be 354.75 F g-1 and 375.32 F g-1 at 1 mV s-1 and 1 A g-1, respectively, for NCO26 in supercapacitor studies. The charge stored via capacitive and diffusion-controlled processes was determined using Power's law and Trasatti plot. An asymmetric supercapacitor device shows a specific capacitance of 122.2 F g-1 at a current density of 1 A g-1 and exhibits a retention of 74.3% after 5000 cycles. An energy density of 67.89 W h kg-1 and a power density of 1 kW kg-1 at a current density of 1 A g-1 are observed.

Tuning band alignment and optical properties of 2D van der Waals heterostructure via ferroelectric polarization switching

Favourable band alignment and excellent visible light response are vital for photochemical water splitting. In this work, we have theoretically investigated how ferroelectric polarization and its reversibility in direction can be utilized to modulate the band alignment and optical absorption properties. For this objective, 2D van der Waals heterostructures (HTSs) are constructed by interfacing monolayer MoS2 with ferroelectric In2Se3. We find the switch of polarization direction has dramatically changed the band alignment, thus facilitating different type of reactions. In In2Se3/MoS2/In2Se3 heterostructures, one polarization direction supports hydrogen evolution reaction and another polarization direction can favour oxygen evolution reaction. These can be used to create tuneable photocatalyst materials where water reduction reactions can be selectively controlled by polarization switching. The modulation of band alignment is attributed to the shift of reaction potential caused by spontaneous polarization. Additionally, the formed type-II van der Waals HTSs also significantly improve charge separation and enhance the optical absorption in the visible and infrared regions. Our results pave a way in the design of van der Waals HTSs for water splitting using ferroelectric materials.

Insight into time-correlated structure and interfacial evolvement of nanocomposite and semiconductor heterostructure for advanced fuel cells

Super ionic channel or shuttle correlated with interfacial engineering of nanocomposite structure and semiconductor-based material electrolytes has shown great potential in electrochemical applications, such as photochemical water splitting or low temperature advanced fuel cell. By adjusting apriority composition between n and p components, the up-to-date semiconductor-ionic membrane fuel cells (SIMFCs) exhibit the improved performance, especially for high ionic conductivity and power outputs at lower temperature. Facing the commercialization of novel advanced ceramic cells, a combined literature survey and phenomenological analysis is proposed to interpret the difference between the current-voltage curve and stability performance of low temperature solid oxide fuel cell (LTSOFC). Meanwhile, it is experimentally determined that the time constant, which is closely related to the interfacial structure and heterostructure, has played a great role in the cell properties. Herein, steady state instead of transient characteristic is preferred, dedicating to provide much more reliable data. Among several prototype cells on semiconductor-based electrolyte, only the candidate that can resist the high current operation shows suppressing inside electronic leakage and survives in short-term test. The results illustrate that though semiconductor-based nanocomposite or heterostructure is an effective methodology in developing low temperature ceramic fuel cells, its durability and the risk of short-circuit should be taken with much care.