Water Splitting Activity Research Articles

Band gap engineering of Au doping and Au – N codoping into anatase TiO2 for enhancing the visible light photocatalytic performance

We investigate anatase TiO2 doping with Au to determine the change in the band gap energy and optoelectronic properties using experimental and theoretical analysis. The structural analysis using XRD patterns revealed that the synthesized materials primarily exhibited an anatase phase of TiO2, with no impurity peaks observed. However, as the concentration of Au increased, additional diffraction peaks corresponding to Au crystalline phases were detected, indicating successful doping. Furthermore, the crystallite size was found to decrease with increasing Au concentration. We observe that the band gap reduces through substitution of Au into the TiO2 lattice from 3.09 eV to 2.78 eV, demonstrating the feasibility of bandgap tuning of the TiO2 system. A redshift for Au doped TiO2 is observed from absorption spectroscopy and optical absorption intensity using hybrid density functional theory, facilitating visible light absorption, although with potential electron-hole recombination limitations. To enhance a visible light photocatalytic activity for water splitting, we extend our work to explore the impact of N and Au codoping into TiO2 lattice. It reveals that the combination between N and Au leads to a suitable reduction in the band gap width of pure TiO2. Interestingly, Au–N codoping may decrease the effect of photogenerated carriers, produce a new optical absorption feature in the visible region, and enhance the photocatalytic performance of TiO2. This codoping configuration is also a promising photocatalyst for the decomposition of water using visible light without inducing unoccupied states.

The borophene quantum dots scaffolded TiO2 nanocomposite as an efficient photo electrocatalyst for water splitting application

Herein, we are scaffolding borophene quantum dots (BPQDs) on photoactive semiconductor nanomaterial such as TiO2 nanoparticle which shows enhanced photoelectrochemical (PEC) water splitting activity. The BPQDs are synthesized by sonochemical method and then scaffolded onto TiO2 nanoparticles by hydrothermal method. Further, the concentration of BPQDs on TiO2 nanoparticles is optimized for better photoelectrochemical water splitting application. The effective absorption edge is found to be less (2.51 eV) for 2.5 wt% BPQDs scaffolded TiO2 nanoparticles as studied by UV–Visible spectroscopic analysis. Transmission electron microscopic (TEM) images reveal the scaffolding of BPQDs of size (2–9) nm with TiO2 nanoparticles of having the size ∼25 nm. XRD results confirmed the anatase phase of TiO2 nanoparticles and b-rhombohedral boron structure for BPQDs. The FTIR and XPS results confirms the presence of boron functionalized groups in the nanocomposites. The photoluminescence (PL) spectroscopic results revealed the decrease in PL emission intensity for BPQDs/TiO2 nanocomposite indicating the decreased photogenerated charge carriers recombination time. The work function (ϕ) is found to be less for BPQDs/TiO2 nanocomposite signifying the easy release of electrons under the presence of visible light illumination. Further, BPQDs/TiO2 nanocomposite shows the improvement in photoelectrochemical (PEC) water splitting due to the synergistic effects of individual components.

Hollow nanoparticles doped hierarchical hexagonal star shaped cobalt-based phosphosulfides for water splitting

Hollow nanoparticles doped hierarchical hexagonal star shaped cobalt (Co) phosphosulfides (CoS/P) have been prepared with sulphidation and phosphorization of Co-based hydroxides as precursors sequentially. Each corner of a hexagonal star is composed of many branched nanorods. Hollow nanoparticles with an average size of 50 nm are observed on these branches. The resulting CoS/P catalyst shows efficient water splitting activity. These hollow nanoparticles provide more exposed active sites with enhanced reaction activity and reaction rate. The CoS/P could serve as a bifunctional OER and HER catalyst with an overpotential of 320 mV and 210 mV, respectively, at j = 10 mA cm−2. The CoS/P exhibited an overpotential of 470 mV for overall water splitting at j = 10 mA cm−2. Theoretical calculations also confirm the beneficial effect of CoS/P compared with CoS. This novel hierarchical structure is a promising electrocatalyst for overall water splitting.

Nitriding-reduction fabrication of coralloid CoN/Ni/NiO for efficient electrocatalytic overall water splitting

The introduction of nitride in Ni/NiO-based catalytic system for electrocatalystic water splitting via a skillful strategy remains a great challenge. Herein, we proposed a one-step urea nitriding-reduction strategy for the fabrication of novel CoN/Ni/NiO electrocatalyst on carbon cloth (CC). The combination of CoN and Ni/NiO could construct CoN/Ni interface and expose more active sites, thus exhibiting excellent hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) performance in alkaline media. Consequently, CoN/Ni/NiO catalyst exhibited remarkable HER/OER performance with an overpotential of 92 mV/114 mV at 10 mA cm−2 in 1.0 M KOH, along with a low cell voltage of 1.56 V to enhance overall water splitting. In addition, when CoN was introduced in Ni/NiO system, CoN/Ni/NiO displayed high conductivity, large active surface areas, high Faradic efficiency (FE) and remarkable stability. Density functional theory (DFT) calculations demonstrated that CoN/Ni/NiO possessed a decreased d-band center beneficial for optimizing the energy barrier of intermediates. Specifically, the ΔGH2O (0.088 eV) and ΔGH* (0.18 eV) in HER and the ΔGOOH* (1.4 eV) of rate determining step (O*→OOH*) in OER of CoN/Ni/NiO catalyst were optimized to achieve high water splitting activity. Simultaneously, for adsorbed H2O on CoN/Ni/NiO, the OH bond length extended from 0.975 to 1.110 Å, and the bond angle enlarged from 104.271 to 109.471°, thereby directly demonstrating the excellent HER/OER performance of CoN/Ni/NiO.

Tuning the interface of MIMII(OH)F@MIMII1-xS (MⅠ: Ni, Co; MⅡ: Co, Fe) by atomic replacement strategy toward high performance overall water splitting

Constructing heterostructure is considered as one of the most promising strategies to reveal high efficiency hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) performance. Nevertheless, it is highly challenging to obtain stable interfaces and sufficient active sites via conventional method. In addition, Ni, Co and Fe elements share the valence electron structures of 3d6-84s2, the appropriate integration of these metals to induce synergistic effect in multicomponent electrocatalysts can enhance electrochemical activity. Herein, in this work, the MIMII(OH)F@MIMII1-xS (NiFe(OH)F@NiFe1-xS, NiCo(OH)F@NiCo1-xS, CoFe(OH)F@CoFe1-xS) autogenous heterostructure on nickel foam are constructed. As a result, NiFe(OH)F@NiFe1-xS-0.05, NiCo(OH)F@NiCo1-xS-0.05, and CoFe(OH)F@CoFe1-xS-0.05 demonstrate outstanding overpotential for HER (70 mV, 90 mV, 81 mV at −10 mA cm−2) and OER (370 mV, 470 mV, 370 mV at 10 mA cm−2) in alkaline electrolyte, while the overpotential for HER is 176 mV, 189 mV, 167 mV at −10 mA cm−2 and corresponding OER is 290 mV, 390 mV, 300 mV at 10 mA cm−2 in simulated seawater, respectively. In addition, the NiFe, NiCo, CoFe-based electrolyzer acquire favorable overall water splitting activity in alkaline (1.72 V, 1.87 V, 1.66 V) and simulated seawater (1.73 V, 1.75 V, 1.69 V) at 10 mA cm−2. Overall, the above results authenticate the feasibility of developing autogenous heterostructure electrocatalysts for providing hydrogen and oxygen in alkaline and simulated seawater.

Highly-Efficient Ni@CuS/SGCN Nanocomposite with Superior Bifunctional Electrocatalytic Activity for Water Splitting

The contemporary world faces significant challenges with the depletion of non-renewable energy sources and the escalation of global temperatures. Using H2 as an energy source is a sustainable, renewable, and environmentally friendly alternative. Electrochemical water splitting using an efficient electrocatalyst is an optimistic approach for hydrogen production. The primary concern is the development of a durable, cost-effective, and highly efficient bifunctional electrocatalyst to enhance electrochemical water splitting. The present investigation employs CuS as the electrocatalyst, followed by the implementation of two techniques, doping and composite material synthesis, to enhance its electrocatalytic characteristics. CuS samples doped with varying weight percentages of Ni (2, 4, 6, 8, and 10 wt.%) and a composite material of 6% Ni@CuS with SGCN were synthesized using the co-precipitation method. The electrocatalysts were studied by characterization techniques such as SEM, EDX, FTIR, and XRD. Doping and composite material synthesis enhance the electrochemical water-splitting activity, as LSV, CV, EIS, and Chronopotentiometry analyses demonstrated. The electrochemical water splitting process exhibits maximum performance when utilizing Ni@CuS/SGCN, resulting in a low overpotential of 380 mV for OER and 178 mV for HER, achieving a current density of 10 mA cm−2. The findings indicate that composite Ni@CuS/SGCN can potentially serve as an electrocatalyst for water splitting.

Heterointerface manipulation in the architecture of Co-Mo2C@NC boosts water electrolysis

Heterostructures with tunable electronic properties have shown great potential in water electrolysis for the replacement of current benchmark precious metals. However, constructing heterostructures with sufficient interfaces to strengthen the synergistic effect of multiple species still remains a challenge due to phase separation. Herein, an efficient electrocatalyst composed of a nanosized cobalt/Mo2C heterostructure anchored on N−doped carbon (Co−Mo2C@NC) was achieved by in situ topotactic phase transformation. With the merits of high conductivity, hierarchical pores, and strong electronic interaction between Co and Mo2C, the Co−Mo2C@5NC−4 catalyst shows excellent activity with a low overpotential for the hydrogen evolution reaction (HER, 89 mV@10 mA cm−2 in alkaline medium; 143 mV@10 mA cm−2 in acidic medium) and oxygen evolution reaction (OER, 356 mV@10 mA cm−2 in alkaline medium), as well as high stability. Furthermore, this catalyst in an electrolyzer shows efficient activity for overall water splitting and long−term durability. Theoretical calculations reveal the optimized adsorption−desorption behaviour of hydrogen intermediates on the generated cobalt layered hydroxide (Co LDH)/Mo2C interfaces, resulting in boosting alkaline water electrolysis. This work proposes a new interface−engineering perspective for the construction of high−activity heterostructures for electrochemical conversion.

Superb Bifunctional Water Electrolysis Activities of Carbon Nanotube-Decorated Lanthanum Hydroxide Nanocomposites

For highly efficient hydrogen production from electrocatalytic water electrolysis, developing a high-fidelity electrocatalyst is pivotal. Herein, we demonstrated the excellent water-splitting performances of the carbon allotrope-decorated rare earth oxide nanocomposite system, which was composed of lanthanum hydroxide (La(OH)3) and carbon nanotube (CNT). The nanocomposites of CNT-La(OH)3 were fabricated via facile ultrasonication using La(OH)3 nanoparticles and CNT nanofibers, and they exhibited excellent bifunctional water-splitting activities. For the hydrogen evolution reaction, CNT-La(OH)3 showed low values of both overpotential (150 mV) and Tafel slope (113 mV/dec) in 1 M KOH at -10 mA/cm2. Additionally, for the oxygen evolution reaction, CNT-La(OH)3 also displayed small values for their overpotential (310 mV) as well as the Tafel slope (39 mV/dec). Furthermore, both bifunctional hydrogen- and oxygen-evolution reactions were confirmed to be stable in chronopotentiometric tests. From the material characterization and the electrochemical characterization, such excellent bifunctional water electrolysis performances were ascribed to the synergetic effects of hybridization of La(OH)3 (i.e., a large number of electrochemically active sites of 304 cm2) and CNT (i.e., high charge transport conductivity). The results specify that the present CNT-La(OH)3 nanocomposite system possesses ample aptitude as a superior electrocatalyst for next-generation hydrogen production technology.

Nanostructured Pt@RuOx catalyst for boosting overall acidic seawater splitting

In the domain of acidic water splitting, designing bifunctional catalysts that marry high activity with enduring stability is a formidable challenge. Herein, we have constructed platinum-containing ruthenium oxide nanoparticles (Pt@RuOx NPs) to achieve excellent overall water splitting performance in acidic electrolytes. Pt@RuOx NPs demonstrate exceptional catalytic activity for both the hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) in acidic seawater, requiring overpotentials of only 20 and 157 mV, respectively to achieve a current density of 10 mA cm−2. Furthermore, in 0.5 M H2SO4, this catalyst exhibits high HER (19 mV) and OER (236 mV) catalytic activities. The two-electrode water splitting system composed of bifunctional Pt@RuOx NPs requires cell voltages of only 1.442 and 1.465 V to deliver a current density of 10 mA cm−2 in acidic seawater and 0.5 M H2SO4. Remarkably, this catalyst displays remarkable stability in the water splitting process. It is shown that the introduction of Pt could augment oxygen vacancies and enhance catalytic activity significantly. The synergy between Pt and Ru further contributes to the improved performance. Additionally, we have observed that acidic seawater holds distinct advantages for acidic water splitting, along with a thorough exploration of the relationship between Cl− concentration and catalytic performance. This study not only provides a strategy to improve the catalytic activity and stability of ruthenium-based catalysts for water splitting in acidic environments, but also unveils the promoting effect of Cl− on the catalytic activity in acidic water splitting.

Self-supporting hierarchical Co3O4-nanowires@NiO-nanosheets core-shell nanostructure on carbon foam to form efficient bifunctional electrocatalyst for overall water splitting

Designing cost-effective and robust bifunctional electrocatalysts for oxygen evolution reaction (OER) and hydrogen evolution reaction (HER) is highly desired in hydrogen production from overall water splitting, but still suffers great challenges due to the sluggish catalytic OER/HER kinetics. In this paper, a surface/defect engineering strategy is developed to synthesize three-dimensional (3D) carbon foam (CF)-supported unique hierarchical Co3O4 nanowires@NiO nanosheets core–shell nanostructured catalyst (NiO@Co3O4/CF) with rich oxygen-vacancies as a novel bifunctional catalyst for alkaline water splitting electrolysis. Benefited from the synergy of the 3D hierarchical core–shell structure and rich oxygen vacancies, the as-obtained NiO@Co3O4/CF shows both excellent OER (η200 = 325 mV, η500 = 374 mV) and HER (η10 = 104 mV) activities with low Tafel slopes (64.26 mV dec−1 for OER and 109.14 mV dec−1 for HER, respectively) and outstanding stability. A simple overall water splitting electrolysis cell assembled by this bifunctional NiO@Co3O4/CF as both OER and HER catalysts requires only a cell voltage of 1.53 V to obtain the current density of 10 mA cm−2 and displays a long-term stability. This work has successfully developed an approach for rational design and novel synthesis of metal oxide hybrids as bifunctional electrocatalysts with high activity and stability for overall water splitting.

Unveiling the Synergistic Potential of Laser Chemical Solid‐Phase Deposition of Atomic Platinum‐Metal Layer on 2D Materials for Bifunctional Catalysts

AbstractThe formation of high‐density atomic metal layers on 2D materials enhances catalytic device development by providing a large surface area, precise control over active sites, and enhanced reactivity. Here, pulsed laser‐induced chemical solid‐phase deposition (LCSD) is introduced for achieving high‐density atomic metal layers. By leveraging high‐density plasma generated via pulsed nanosecond laser irradiation of thin salt layers on 2D materials, atomic‐scale metals are deposited onto abundant nucleation sites, creating dense atomic‐metal layers. This study engineers layered double hydroxide (LDH) materials layered with atomic platinum‐based alloys, exhibiting exceptional catalytic activity for overall water splitting. LDH's excellent oxygen evolution performance combined with remarkable advances in hydrogen evolution catalysis are achieved. Introducing a second element improves Pt layer dispersion and uniformity, resulting in extraordinary Pt distribution density and minimal overpotential. The LDH and Pt‐metal combination creates powerful synergistic effects, significantly enhancing catalytic performance and enabling superior bifunctional catalysts for water splitting. LCSD effectively fabricates stable nanocomposites designed for electrocatalytic applications, leveraging unique structures of atom‐scale metal‐supported composite 2D materials, enhancing overall electrocatalytic performance. This breakthrough impacts energy conversion and environmental protection, broadening electrocatalysis and revolutionizing atom‐scale metal‐supported composite 2D materials. Its practical applications span various areas, contributing to sustainable energy solutions and environmental preservation.

Stainless steel as an electrocatalyst for overall water splitting under alkaline and neutral conditions

The development process for an effective catalyst for electrochemical water splitting must consider properties such as chemical and mechanical stability, corrosion resistance, and abundance alongside efficiency. In this work, a detailed electrochemical evaluation of four types of commercially available AISI stainless steel (302, 304, 316, and 321) was performed for their electrocatalytic activity, stability, and corrosion resistance in overall water splitting under alkaline (pH 14.00) and near-neutral conditions (pH 6.26). Using AISI plates directly as an anode or cathode, a current density of 10 mA cm−2 was obtained at η ≈ 0.38 V for OER and η ≈ 0.43 V for HER in 1 M KOH. Although all of the tested types have proved to be efficient electrocatalysts, detailed electrochemical studies have distinguished certain differences between the AISI types, depending mainly on the composition peculiarities. A detailed corrosion evaluation has revealed that although all measured stainless steels are sensitive to the oxidative environment, their corrosion rate does not exceed 3.3 µm per year.

Multilevel hollow hierarchical heterostructure with DB-IEF and space-confined effect for enhanced bifunctional PHE/HER activity

In photocatalytic/electrocatalytic water splitting processes, charge carriers are the main limiting factor of enhanced yield, and the enhanced charge dynamics related to the generation, transport, separation and utilization of charge is considered to be an effective measure to solve the above problems. In this study, multilevel hollow hierarchical In2S3/ZnIn2S4/CdIn2S4 (IS/ZIS/CIS) with heterogeneous spatial confinement was successfully prepared by one-step solvothermal method. The strong dual cascade built-interface electric field (DB-IEF) of the IS, ZIS and CIS contact interfaces (ISⅠZIS and ZISⅠCIS) is beneficial for migrating electrons and tailoring the electronic structures of the active centers near the ISⅠZIS and ZISⅠCIS interfaces. The as-constructed IS/ZIS/CIS shows outstanding bifunctional photocatalytic/electrocatalytic water splitting activity, which can not only offer high electrocatalytic activities toward HER with a low overpotential of 61 mV (vs. RHE) at 10 mA ·cm−2, with low Tafel slopes of 68 mV·dec-1 in alkaline solutions, but also achieve a higher H2 evolution rate of 4.42 mmol g−1·h−1. Meanwhile, the Brunauer-Emmett-Teller surface area (BET) and pore size distribution revealed that multilevel hollow hierarchical IS/ZIS/CIS heterostructure owns hierarchical microporous/mesoporous structure, which facilitates light absorption and multiple reflections. The efficiently interfacial charge transfer and bifunctional catalytic activity could be attributed to the established DB-IEF and spatial confinement effect could drive carrier transmission, realize effective charge separation, utilization, and prolong lifetimes. This work can provide a new synthesis strategy of establishing the hierarchical heterostructure catalysts for boosting charge transfer and photocatalytic/electrocatalytic water splitting.

Modulating P-S anions of graphene supported amorphous nickel-iron nanocomposites by plasma to optimize overall water splitting activity

Hydrogen production by electrolysis of water is a key technology that has the potential to aid in the transition towards green sources of energy. In this regard, graphene-supported bifunctional electrocatalysts have shown to promote both oxygen evolution and hydrogen evolution processes. Although they are considered as one of the most potential electrocatalysts, modulation of their morphological structures and electronic configurations is challenging. Here, an efficient bifunctional electrocatalyst of graphene-supported NiFe-LDH with phosphorus-sulfur anion coordination is prepared based on the RF plasma treatment strategy. Reasonable P and S anion ratios optimize the partial coordination environment and crystal state, and effectively regulate the adsorption of OH∗, OOH∗, and protons, which consequently enhance the OER/HER performance. Plasma treatment generates vacancy defect structures for the catalyst, which modulates the surface morphology and electronic structure. Optimized graphene-supported NiFe-LDH catalysts with phosphorus-sulfur anion modulation show excellent electrocatalytic performance with 228 mV overpotentials for OER at 100 mA cm−2, in alkaline environments with excellent stability. This study offers recommendations for designing catalysts to produce effective water splitting.

Unprecedented iron-based photoelectrocatalysts@graphene foam composites as electrolyzing nanomaterials for water splitting in a neutral environment

Using nonprecious metal catalysts to efficiently produce large capacities of H2 and O2 from water splitting through the photoelectrolysis path is a crucial objective. The FeS2/α-Fe2O3 composite is first synthesized using thiourea under hydrothermal conditions and is subsequently combined with different weight ratios of graphene foam (GF; 6–20 %). The catalyst FeS2/α-Fe2O3@11 %GF demonstrates the highest photoelectrochemical water splitting activity at an excessive potential of 0.17 V, accomplishing a current density of 10 mA cm−2 and a Cdl of 2.14 mF cm−2 for HER, exceeding Pt/C results (0.53 V, 2.0 mF cm−2). OER, on the other hand, exhibits an overpotential of 0.18 V at 10 mA cm−2 and a low Tafel slope value of 77.9 mV dec−1, causing a very considerable rise in the reaction kinetics with a noticeably stable behavior. Total water splitting was achieved using the FeS2/α-Fe2O3@11 %GF || FeS2/α-Fe2O3@11 %GF electrolyzer with a small cell voltage of 1.63 V to produce 10 mA cm−2. Due to the significant interfacial effects produced by the well-integrated GF, boosted pore volume and surface area, abundance of accessible sites of activity, and growing Fe2+/Fe3+ ratio, which significantly improved electron transfer and electrolyte transport, the three-component system improved its ability to achieve efficient water splitting.

A theoretical investigation of two-dimensional Antimonene/ZnSe heterostructure for photocatalytic water splitting: A DFT study

Two dimensional materials have achieved tremendous importance in the field of photocatalysis, optoelectronics, and in some advance fields. In this era of environmental crisis, production of non-polluting fuel like hydrogen is a main challenge which can be solved with photocatalytic water splitting. Therefore, in this study a heterostructure of antimonene and ZnSe monolayer has been investigated for its photocatalytic activity of water splitting along with its geometric, electronic, and optical properties using first principles calculations. The designed heterostructure is predicted to possess a type-II band alignment which is useful for carrier separation and hence oxidation and reduction of water. A built-in electric field was also observed which fastens this transfer of charge carriers among the conduction or valence bands and also prevents them from recombination. A good optical absorption also strengths its case for being a good photocatalyst for splitting of water and opens a path regarding future applications.

Hydrogen and oxygen production on Ag2O/NiO hybrid nanostructures via electrochemical water splitting

Among the different available methods, hydrogen production by electrocatalytic water splitting is the most attractive method. Here, Ag2O/NiO hybrid nanostructures with different molar ratios of silver and nickel ions were synthesized by co-precipitation method. Nickel oxide and silver oxide nanostructures was also prepared to compare with Ag2O/NiO nanocomposites. Investigations indicated that the as-prepared Ag2O/NiO nanocomposite with an equal molar ratio of metal ions shows high water splitting activity in 1 M KOH solution and only 430 and 140 mV are needed as overpotentials under a current density of 10 mA cm−2 for oxygen and hydrogen evolution reactions (OER and HER), respectively. Ag2O/NiO has the largest electrochemically active surface area, the lowest Tafel slope, the smallest semicircle diameter in the Nyquist plots, and the lowest charge transfer resistance for both OER and HER among all tested nanomaterials. Furthermore, Ag2O/NiO showed excellent stability for OER and HER for at least 30 h.

Interface strain engineering of Ir clusters on ultrathin NiO nanosheets for electrochemical water splitting over 1800 hours

Strain engineering of two-dimensional (2D) material interfaces represents a powerful strategy for enhancing the electrocatalytic activity of water splitting. However, maintaining catalytic stability under various harsh conditions by introducing interface strain remains a great challenge. The catalyst developed and evaluated herein comprised Ir clusters dispersed on 2D NiO nanosheets (NSs) derived from metal organic frameworks (Ir@NiO/CBDC), which displays a high activity and stability under all pH conditions, and even a change of only 1% in the applied voltage is observed after continuous electrocatalytic operation for over 1800 h under alkaline conditions. Through combined experimental and computational studies, we found that the introduced interfacial strain contributes to the outstanding structural stability of the Ir@NiO/CBDC catalyst, arising from its increased Ir and Ni vacancy formation energies, and hence suppressing its leaching. Moreover, strain also enhances the kinetically sluggish electrocatalytic water splitting reaction by optimizing its electronic structure and coordination environment. This work highlights the effects of strain on catalyst stability and provides new insights for designing widely applicable electrocatalysts.

Insights into the structural, and functionality of RuO2/TiO2 and Ni(OH)2/RuO2/TiO2 for water splitting and dye degradation

Heterogeneous catalysis and the uniform interface are playing a vital role in environmental protection and are amenable to photoelectrochemical transformation reactions. Herein, a mixed metal oxide catalyst composed of RuO2 or RuO2/Ni(OH)2 supported on TiO2 is developed via the facile sol-gel method. Structural and morphological analyses confirm the presence of RuO2 and Ni(OH)2 beside the anatase phase in the composite catalysts . The band gap of TiO2 is tuned after contacting with RuO2 (2.35 eV) and the surface area is doubled. XPS shows the existence of a high level of defects and VSM demonstrates a ferromagnetic-like hysteresis loop for TiRu. A fast positron annihilation is observed of TiRu compared to TiO2 indicating smaller free volume defects in the composite powders. The oxidation tests of water display a high current density of 18.6 mA/cm2 and dimensional stability for the TiRu sample with negligible electroactivity for TiRuNi. On the other hand, the photoelectrochemical water splitting activity is found to be the lowest for the composite samples compared to TiO2. The photocatalytic efficiency is further examined via the removal of two industrial dyes (Dianix Blue and Indigo Carmine dyes) and the performance is correlated to the results obtained from Mott-Schottky.

Automated Construction of a Photocatalysis Dataset for Water-Splitting Applications

We present an automatically generated dataset of 15,755 records that were extracted from 47,357 papers. These records contain water-splitting activity in the presence of certain photocatalysts, along with additional information about the chemical reaction conditions under which this activity was recorded. These conditions include any co-catalysts and additives that were present during water splitting, the length of time for which the photocatalytic experiment was conducted, and the type of light source used, including its wavelength. Despite the text extraction of such a wide range of chemical reaction attributes, the dataset afforded good precision (71.2%) and recall (36.3%). These figures-of-merit were calculated based on a random sample of open-access papers from the corpus. Mining such a complex set of attributes required the development of novel techniques in knowledge extraction and interdependency resolution, leveraging inter- and intra-sentence relations, which are also described in this paper. We present a new version (version 2.2) of the chemistry-aware text-mining toolkit ChemDataExtractor, in which these new techniques are included.