국내 광전기화학 수소생산의 경제성 평가

김봉진,김종욱 한국수소및신에너지학회 2010 한국수소 및 신에너지학회논문집 Vol.21 No.1

This paper deals with an economic evaluation of domestic immersing type photoelectrochemical hydrogen production. We also make some sensitivity analysis of hydrogen production prices by changing the values of input factors such as the initial capital cost, the solar to hydrogen conversion efficiency, and the system duration time. The hydrogen production price of the immersing type photoelectrochemical system was estimated as 8,264,324 won/kgH2. It is expected that the production cost by photoelectrochemical hydrogen production can be reduced to 26,961 won/kgH2 if the solar to hydrogen conversion efficiency is increased to 14%, the system duration time is increased to 20,000 hours, and the initial capital cost is decreased to 10% of the current level. The photoelectrochemical hydrogen production is evaluated as uneconomical at this time, and we need to enhance the solar to hydrogen conversion efficiency and the system duration time as well as to reduce prices of the system facilities.

Sn Doping into Hematite Nanorods for High-Performance Photoelectrochemical Water Splitting

Hien, Truong Thi,Quang, Nguyen Duc,Hung, Nguyen Manh,Yang, Haneul,Chinh, Nguyen Duc,Hong, Soonhyun,Hieu, Nguyen Minh,Majumder, Sutripto,Kim, Chunjoong,Kim, Dojin The Electrochemical Society 2019 Journal of the Electrochemical Society Vol.166 No.15

<P>Photoelectrochemical water splitting is of great attention due to its environmental friendly generation of clean fuels. Hematite (α-Fe<SUB>2</SUB>O<SUB>3</SUB>) is considered one of the promising candidates due to its intrinsic properties for the high performance photoelectrochemical electrode such as favourable bandgap (2.0–2.2 eV), a suitable energy band position, non-toxicity, low cost, and excellent chemical stability. Herein, we report about Sn-doped hematite nanorods and their implementation as photoanodes for photoelectrochemical water splitting. We provide the simple but efficient route to incorporate the Sn into the hematite without structural damage in the nanostructure and scrutinize the effect of Sn dopant on the photoelectrochemical activity of the hematite. By the two-step heat-treatment process, Sn can be successfully incorporated into the hematite, which reveals the enhanced photoelectrochemical responses compared with undoped hematite. We elaborate the effect of Sn dopant in the hematite on the photoelectrochemical activities, thereby the optimum concentration of Sn dopant can be suggested. In addition, the catalyst layer of the cobalt phosphate is introduced to further increase the photoelectrochemical performance of Sn-doped hematite nanorods.</P>

Photoelectrochemical properties of hematite thin films grown by MW-CBD

Choi, Hayoung,Hong, Yaejin,Ryu, Hyukhyun,Lee, Won-Jae Elsevier 2018 Surface & coatings technology Vol.333 No.-

<P><B>Abstract</B></P> <P>In this study, Fe<SUB>2</SUB>O<SUB>3</SUB> thin films were grown on a Fe<SUB>2</SUB>O<SUB>3</SUB> buffered-film using the microwave chemical bath deposition (MW-CBD) method with different FeCl<SUB>3</SUB> precursor concentrations. The morphological, optical, structural, electrical and photoelectrochemical properties of the Fe<SUB>2</SUB>O<SUB>3</SUB> thin films were studied according to the different precursor concentrations, and the relationships between each property were systematically analyzed. From the study, we found that the morphological, structural and electrical properties greatly influenced the photoelectrochemical properties. As a result, the 0.1M sample, which has good morphological, structural, and electrical properties has the highest photocurrent density value of 0.31mA/cm<SUP>2</SUP> (at 0.5V vs. SCE), and has good photostability properties. Field emission scanning electron microscopy (FE-SEM) and atomic force microscope (AFM) were used to characterize the morphological properties of the Fe<SUB>2</SUB>O<SUB>3</SUB> thin films. X-ray diffraction (XRD) was used to study the structural properties, UV–visible spectroscopy was used to measure the optical properties, electrochemical impedance spectroscope (EIS) was used to characterize the electrical properties and a three-electrode potentiostat was used to measure the photoelectrochemical properties.</P> <P><B>Highlights</B></P> <P> <UL> <LI> The Fe<SUB>2</SUB>O<SUB>3</SUB> photoelectrode was grown by microwave chemical deposition (MW-CBD) method. </LI> <LI> The effects of the FeCl<SUB>3</SUB> concentration on the Fe<SUB>2</SUB>O<SUB>3</SUB> photoelectrode were investigated. </LI> <LI> The properties of Fe<SUB>2</SUB>O<SUB>3</SUB> photoelectrode were largely dependent on the FeCl<SUB>3</SUB> concentration. </LI> <LI> The 0.1 M-sample had the best photoelectrochemical properties. </LI> </UL> </P>

산화구리의 광전기화학적 거동 특성

윤홍관,홍순현,김도진,김천중,Yun, Hongkwan,Hong, Soonhyun,Kim, Dojin,Kim, Chunjoong 한국재료학회 2019 한국재료학회지 Vol.29 No.1

Recent industrialization has led to a high demand for the use of fossil fuels. Therefore, the need for producing hydrogen and its utilization is essential for a sustainable society. For an eco-friendly future technology, photoelectrochemical water splitting using solar energy has proven promising amongst many other candidates. With this technique, semiconductors can be used as photocatalysts to generate electrons by light absorption, resulting in the reduction of hydrogen ions. The photocatalysts must be chemically stable, economically inexpensive and be able to utilize a wide range of light. From this perspective, cuprous oxide($Cu_2O$) is a promising p-type semiconductor because of its appropriate band gap. However, a major hindrance to the use of $Cu_2O$ is its instability at the potential in which hydrogen ion is reduced. In this study, gold is used as a bottom electrode during electrodeposition to obtain a preferential growth along the (111) plane of $Cu_2O$ while imperfections of the $Cu_2O$ thin films are removed. This study investigates the photoelectrochemical properties of $Cu_2O$. However, severe photo-induced corrosion impedes the use of $Cu_2O$ as a photoelectrode. Two candidates, $TiO_2$ and $SnO_2$, are selected for the passivation layer on $Cu_2O$ by by considering the Pourbaix-diagram. $TiO_2$ and $SnO_2$ passivation layers are deposited by atomic layer deposition(ALD) and a sputtering process, respectively. The investigation of the photoelectrochemical properties confirmed that $SnO_2$ is a good passivation layer for $Cu_2O$.

태양전지를 이용한 국내 Window Type 광전기화학 수소생산의 경제성 평가

김봉진,김종욱 한국수소및신에너지학회 2010 한국수소 및 신에너지학회논문집 Vol.21 No.6

This paper deals with an economic evaluation of domestic window type photoelectrochemical hydrogen production utilizing solar cells. We make some sensitivity analysis of hydrogen production prices by changing the values of input factors such as the initial capital cost, the solar to hydrogen conversion efficiency, and the system duration time. The hydrogen production price of the window type photoelectrochemical system was estimated as 1,168,972 won/kgH2. It is expected that hydrogen production cost can be reduced to 47,601 won/kgH2 if the solar to hydrogen conversion efficiency is increased to 14%, the system duration time is increased to 20,000 hours, and the initial capital cost is decreased to 25% of the current level. We also evaluate the hydrogen production cost of the water electrolysis using the electricity produced by solar cells. The corresponding hydrogen production cost was estimated as 37,838 won/kgH2. The photoelectrochemical hydrogen production is evaluated as uneconomical at this time, and we need to enhance the solar to hydrogen conversion efficiency and the system duration time as well as to reduce prices of the system facilities.

전기방사와 수열합성법으로 제작한 광전화학셀 전극용 나노 계층형 아연산화물 구조 연구

이환표,정혁,김옥길,김효진,김도진,Yi, Hwanpyo,Jung, Hyuck,Kim, Okkil,Kim, Hyojin,Kim, Dojin 한국재료학회 2013 한국재료학회지 Vol.23 No.11

Photoelectrochemical cells have been used in photolysis of water to generate hydrogen as a clean energy source. A high efficiency electrode for photoelectrochemical cell systems was realized using a ZnO hierarchical nanostructure. A ZnO nanofiber mat structure was fabricated by electrospinning of Zn solution on the substrate, followed by oxidation; on this substrate, hydrothermal synthesis of ZnO nanorods on the ZnO nanofibers was carried out to form a ZnO hierarchical structure. The thickness of the nanofiber mat and the thermal annealing temperature were determined as the parameters for optimization. The morphology of the structures was examined by field-emission scanning electron microscopy, transmission electron microscopy, and X-ray diffraction. The performance of the ZnO nanofiber mat and the potential of the ZnO hierarchical structures as photoelectrochemical cell electrodes were evaluated by measurement of the photoelectron conversion efficiencies under UV light. The highest photoconversion efficiency observed was 63 % with a ZnO hierarchical structure annealed at $400^{\circ}C$ in air. The morphology and the crystalline quality of the electrode materials greatly influenced the electrode performance. Therefore, the combination of the two fabrication methods, electrospinning and hydrothermal synthesis, was successfully applied to fabricate a high performance photoelectrochemical cell electrode.

Bandgap Reduction and Enhanced Photoelectrochemical Water Electrolysis of Sulfur-doped CuBi2O4 Photocathode

김은화,이상한,유상우 대한금속·재료학회 2023 대한금속·재료학회지 Vol.61 No.2

As interest in hydrogen energy grows, eco-friendly methods of producing hydrogen are beingexplored. CuBi2O4 is one of the p-type semiconductor cathode materials that can be used forphotoelectrochemical hydrogen production via environment-friendly water electrolysis. CuBi2O4 has abandgap of 1.5 – 1.8 eV which allows it to photogenerate electrons and holes from the absorption of visiblelight. This study investigated the effect of sulfur doping on the bandgap and photoelectrochemical waterreduction properties of CuBi2O4. Sulfur-doped CuBi2O4 thin films were electrochemically synthesized usinga nitrate-based precursor solution with thiourea. This was followed by two-step annealing in an Aratmosphere, which effectively prevented the oxidation of sulfur. Sulfur doping up to 0.1 at% led to expansionof the lattice volume of the CuBi2O4. The bandgap was reduced from 1.9 eV to 1.5 eV with increasing dopingconcentration, which resulted in the enhancement of photoelectrochemical current density by ~240%. X-rayphotoelectron spectroscopy showed that sulfur-doping reduced oxygen vacancies with increasing dopingconcentration, confirming that the enhanced photoelectrochemical properties resulted from the reduction inbandgap, not from any extrinsic factor such as oxygen vacancies. Further studies of sulfur-doped CuBi2O4 toimprove surface coverage are expected to lead to a more promising photoelectrochemical cathode material.

광전극 소재를 중심으로 본 광전기화학적 이산화탄소 전환기술 동향 분석

박이슬(Yiseul Park),최지나(Jina Choi) 한국에너지기후변화학회 2016 에너지기후변화학회지 Vol.11 No.1

This work is a short review of recent studies on photoelectrochemical reduction of carbon dioxide (CO₂). Photoelectrochemical reduction of CO₂ is a light-driven CO₂ reduction, which harnesses solar energy to convert CO₂ into higher-energy products (e.g., liquid fuels). Studies on photoelectrochemical cell have mainly focused on photoelectrochemical H₂ production via water splitting, but, recently, photoelectrochemical reduction of CO₂ have been actively investigated as a part of the artificial photosynthesis studies. In this short review, the recent literature on photoelectrochemical reductions of CO₂ is reviewed. Various photoanode and photocathode materials are compared and different approaches to enhancing solar-to-fuel efficiency and selectivity of target product are described.

Transport of photo-generated electrons and holes in TiO₂/CdS/CdSe core-shell nanorod structure toward high performance photoelectrochemical cell electrode

Quang, Nguyen Duc,Hien, Truong Thi,Chinh, Nguyen Duc,Kim, Dahye,Kim, Chunjoong,Kim, Dojin Elsevier 2019 ELECTROCHIMICA ACTA Vol.295 No.-

<P><B>Abstract</B></P> <P>The novel photoelectrochemical cell with very high photocurrent density (>35 mA/cm<SUP>2</SUP>) is demonstrated by nanoscale architecturing of TiO<SUB>2</SUB>/CdS/CdSe multi-core-shell nanorods. While dimensions of constituting layers, i.e. TiO<SUB>2</SUB> nanorod templates, CdS, and CdSe shell layers, are optimized by thorough investigation of optical and photoelectrochemical responses of each layer, high light absorption through the nanorod geometry and facile transport of the photo-generated electrons and holes along the high conduction path of CdSe and CdS result in the high photoelectrochemical performances. In addition, the microscopic model for the electron and hole transport in the core-shell nanorod is elaborated using the energy band diagram. The demonstration of the high performance PEC electrode as well as the platform to optimize PEC electrodes are highlighted in the current work.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Design of the TiO<SUB>2</SUB>/CdS/CdSe double-sheath core-shell nanorod array. </LI> <LI> Superior photoelectrochemical properties (high photocurrent density). </LI> <LI> Fundamental understanding about the charge transport mechanism of the core-shell nanorod. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>

One-pot synthesis of sulfur and nitrogen codoped titanium dioxide nanorod arrays for superior photoelectrochemical water oxidation

Andoshe, Dinsefa M.,Yim, Kanghoon,Sohn, Woonbae,Kim, Changyeon,Kim, Taemin Ludvic,Kwon, Ki Chang,Hong, Kootak,Choi, Seokhoon,Moon, Cheon Woo,Hong, Seung-Pyo,Han, Seungwu,Jang, Ho Won Elsevier 2018 Applied Catalysis B Vol.234 No.-

<P><B>Abstract</B></P> <P>Despite its abundant, nontoxicity and photochemical stability, titanium dioxide shows low solar water oxidation performance due to low photogenerated carrier transport and wide optical band gap, which results in substantially low photogenerated carrier density that impair the solar to hydrogen conversion efficiency. Herein, highly enhanced water oxidation performance of high-aspect-ratio TiO<SUB>2</SUB> nanorods doped with dual heteroatoms, sulfur and nitrogen, for photoelectrochemical solar water oxidation is demonstrated. The codoped TiO<SUB>2</SUB> NRs have shown enhanced optical absorption coefficient due to the induced impurities energy states near to the top of the valance band and result in a red shift in the optical absorption edges. Consequently, a 2.82 mAcm<SUP>−2</SUP> photocurrent density at 1.23 V vs. RHE is obtained from the sulfur and nitrogen codoped TiO<SUB>2</SUB> nanorods, and pristine TiO<SUB>2</SUB> nanorods photoanode shows 0.7 mAcm<SUP>−2</SUP>. The applied bias photon-to-current conversion efficiency and external quantum efficiency of the codoped TiO<SUB>2</SUB> nanorods are 1.49% and 97.0% at λ = 360 nm and 0.69% and 19.1% at λ = 370 nm for pristine TiO<SUB>2</SUB> nanorods, respectively. Our study offers experimental and theoretical evidence for codoping of sulfur and nitrogen improve the optical and electrical properties of TiO<SUB>2</SUB> for efficient photoelectrochemical solar water oxidation.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Our S, N codoped TiO<SUB>2</SUB> NRs photoanodes synthesized by one-pot synthesis method exhibit the excellent photoelectrochemical performance. </LI> <LI> The influence of dual heteroatom doping with sulfur and nitrogen on optical and electrical properties was elucidated by experiments and theoretical calculation. </LI> <LI> The dual heteroatom doping with sulfur and nitrogen decreases the dopant formation energy and improves the optical absorption coefficient of TiO<SUB>2</SUB> NRs. </LI> <LI> In UV wavelength region, our samples show the incident photon up to a current efficiency of 97%. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>A photoanode prepared using titanium dioxide nanorods Arrays codoped with sulfur and nitrogen shows the highest water oxidation performance relative to cocatalyst-free TiO<SUB>2</SUB> photoanodes reported to date for photoelectrochemical water splitting. The outperformance of the TiO<SUB>2</SUB> (S, N) NRs mainly resulted from the induced energy states between the conduction and valence band of TiO<SUB>2</SUB>, which enhances the optical absorption and charge transport of the TiO<SUB>2</SUB> NRs.</P> <P>[DISPLAY OMISSION]</P>