Alexander Orlov - US grants

Intellectual Merit
The PIs are requesting funds to acquire a scanning mobility particle sizer, a Proton Transfer Time of Flight mass spectrometer (PRToFMS), and an isotope ratio mass spectrometer. This suite of instrumentation will allow the PIs to examine biogeochemical properties and reaction mechanisms, and allow modeling of processes that govern the exchange of organic gaseous and condensed matter between the marine and atmospheric environments. Research efforts enabled by the proposed instrumentation include investigations into: the organic fraction of primary marine aerosols; marine biogenically driven volatile organic compound (VOC) emissions; compound-specific isotopic composition to differentiate between marine and terrestrial emissions; isotopic composition of carbon monoxide trapped in ice cores; chemical transformation of organic aerosol particles; effect of chemical aging on ice nucleation; polychlorinated biphenyl transformations on mineral surfaces; development of novel catalysts for photocatalytic reduction of carbon dioxide into hydrocarbons; sedimentary diagenetic processes and seabed fluxes; and reconstructing food web structure in shallow enclosed bays.

Broader Impacts
The proposed instrumentation will provide expanded analytical capability for the School of Marine and Atmospheric Sciences, as well as across Stony Brook University and Brookhaven National Laboratory. Additionally, the proposed instrumentation will be incorporated into the existing REU program at the institution, as well as into the Science and Technology Entry summer residential program, providing hands-on training opportunities for both undergraduates and secondary school students.

This EArly Grant for Exploratory Research (EAGER) award will develop a strategy of making the concrete more environmentally friendly by using it as adsorbent to remove Nitrogen Dioxide (NO2), therefore offsetting the NO2 emissions originating from cement production and various other sources. NO2 emissions can cause various environmental and health problems. They contribute to formation of acid rain, atmospheric particles and various other toxic substances resulting in health problems, visibility reduction, eutrification and global warming. One of the most prominent results of NO2 emissions is formation of ground level ozone, which is produced in the reaction of NO2 with volatile organic compounds (VOCs) in the presence of sunlight. When formed, it causes adverse effects such as damage to lung tissue and reduction in lung function.

The strategy of using both fresh and aged concrete for NO2 removal offers a significant potential to transform the way the waste concrete is disposed of and recycled. It also brings together such disciplines as structural materials, materials engineering, surface science, environmental chemistry and atmospheric science in an innovative and synergetic manner.

ABSTRACT

Producing hydrogen from water using sunlight and catalysts is a key desirable strategy for solar energy storage and conversion. The process is a form of artificial photosynthesis. Despite significant scientific efforts invested in this field, the quantum efficiency of the water splitting reaction remains low, indicating that new approaches are needed to address this challenging problem.

Investigator Alexander Orlov of SUNY at Stony Brook, NY has considered and worked in the area, investigating a series of semiconductor materials, with some success. Summary observations indicate that despite a respectable quantum efficiency of La/KTaO3 and ZnS based catalysts, these materials are only active under UV radiation, which represents only 5% of the solar energy reaching the earths surface. Therefore, the challenge remains to utilize visible light to initiate the water splitting reaction. The best QE for visible light photocatalysis is only 6.5%, which is significantly below the 10% QE necessary to make this technology commercially viable. In order to achieve a scientific breakthrough in this area, it is important to
develop new photocatalyst approaches to address this challenging problem.

Recently the PI has developed a new procedure for synthesis of sub-1 nm metal nanoclusters containing less than 11 atoms. In preliminary experiments these nanoparticles have exhibited an extraordinary activity in various oxidation reactions as compared to the most active commercially available catalysts. This project will now attempt to explore the reactivity of such particles for the water splitting reaction. The proposed project has a significant potential to develop new catalysts for sustainable energy generation. In addition, it will also have a substantial educational impact, as it will be used to start a new area of environmental research training at the Materials Science and Engineering Department, which will be focused on environmental catalysis and sustainable energy research.

NON-TECHNICAL DESCRIPTION: The efficient conversion of carbon dioxide into fuels has an enormous potential to address both greenhouse emission issues and sustainable energy challenges. Significant challenges exist in producing materials, which can facilitate this conversion by utilizing solar energy, especially the visible part of the solar spectrum. A limited number of known materials exhibit very low quantum efficiency for carbon dioxide conversions, while being activated only by ultraviolet (UV) light. If successful, this project can significantly impact energy and environmental areas by using green routes for producing valuable chemicals. It will reduce carbon dioxide emissions by utilizing sustainable sources of energy, such as sunlight.

TECHNICAL DETAILS: The major obstacle to progress in this scientific area is a lack of understanding of the relationship between synthetic method, micro- and nano-architecture and nanostructure, and the resulting physico-chemical and reactivity properties. Achieving this understanding and developing entirely new fabrication methods, applicable on an industrial scale, are major challenges that must be met before these new functional properties can find actual practical application. Accomplishing these two objectives, one scientific and the other technical, would correspond to a major breakthrough that would make possible a whole range of new applications. This project focuses on synthesis of perovskite-based nanostructured films and powders modified at the nanoscopic level by a variety of techniques that allow chemical doping, control of crystal structure, defect concentration and imposition of unusual new morphologies. This research undertakes an entirely new direction for achieving photocatalytic conversion of carbon dioxide into valuable chemical products. This project aims at exploring several strategies to establish a link between reactivity and physicochemical properties of these materials through both bulk and surface sensitive characterization techniques. This project also seeks a better understanding of the role of dopants in carbon dioxide interfacial reactions when the dopants are introduced in the correct oxidation state, concentrations and location where they can lead to significant increase in catalytic activity. An unusual part of this research is the utilization of doped nanostructured films, where both particle size and composition can be precisely controlled by a new nanofabrication method. Additionally, this project aims at exploring morphological control of perovskite oxides to increase their surface area and light trapping capabilities. Finally this project expands the teaching curriculum and research opportunities at both the graduate and undergraduate levels with significant inclusion of underrepresented students.

TECHNICAL
High-pressure (HP) synthesis is considered specialized and labor-intensive with low throughput and success rates. By integrating the installed infrastructure for theory, HP synthesis, and property measurements at SBU with national synchrotron x-ray and neutron facilities, we aim to unlock the potential of HP as a routine tool for solid-state materials discovery and development. An ab initio evolutionary algorithm for crystal structure prediction provides structure-property relations that can be tested experimentally using in situ scattering techniques. In addition to the precise determination of electronic and catalytic properties, the experimental results provide a feedback loop that validates and improves the predictive capability of the computational search. This strategy is broadly applicable to HP exploratory synthesis, and particularly suitable in the search for oxynitride photocatalysts, since HP favors production of solids, rather than competing reactions that result in breakdown to gaseous products. Pressure also facilitates band gap engineering through careful control over the stoichiometry and the ordering of O/N in closed systems, something difficult to achieve with current ammonolysis routes used at ambient pressure. The development of active nano-gold co-catalysts allows us to rapidly test the activity of even small amounts of recovered material. The funding will train a new generation of young scientists; comfortable with a more integrated approach to materials development that utilizes computational and experimental high-pressure techniques as mainstream tools.

NON TECHNICAL
Although materials synthesis at high pressure has the potential to produce unprecedented and transformative materials, traditional approaches are specialized and labor-intensive, with comparatively low rates of throughput and discovery. By integrating theory, synthesis, and property measurements at Stony Brook with the nation's synchrotron X-ray and neutron facilities, we aim to unlock the potential of high pressure as a routine tool for solid-state materials discovery. Computational search will provide lists of target compositions along with their predicted properties. These targets can be synthesized using high throughput techniques prior to precise determinations of electronic and catalytic properties. These results constitute a feedback loop that provides insight into better predictive capability. This strategy is particularly suitable in the search for oxynitride photocatalysts for use in hydrogen production from sunlight and water. The application of pressure favors the formation of solids rather than competing reactions that result in breakdown to gaseous products, oxygen and nitrogen. The recent development of active nano-gold co-catalysts allows us to rapidly test the activity of even small amounts of recovered material. The funding will train a new generation of young scientists; comfortable with a more integrated approach to materials development that utilizes computational and experimental high-pressure techniques as mainstream tools.

NON-TECHICAL DESCRIPTION: Development of new methods for converting solar energy into fuels offers tremendous potential to address both sustainable energy and environmental issues. Producing hydrogen from water using sunlight and light-activated materials is an attractive strategy for solar energy storage and conversion. Despite tremendous progress in the design of new materials, the efficiency of this conversion process is still very low. To address this challenge, this project focuses on overcoming several bottlenecks in materials science and chemistry by adopting a process that occurs naturally in biological systems. The experimental strategy uses novel composite materials, where oxygen and hydrogen are produced on different semiconductors coupled together. This approach, inspired by natural photosynthesis, is called the Z-scheme.

TECHNICAL DESCRIPTION: Previous studies employing a Z-scheme for water splitting typically involved the use of two different semiconductor powders in aqueous solutions, which are coupled by redox agents that act as an electron shuttle between the two components. In this work, Orlov's group is using an all solid-state Z-scheme system which has the potential advantage of using individual components that are optimized for only one of the water splitting half reactions (water oxidation or water reduction), and placing them in intimate contact to promote charge transfer between them. By eliminating the need for a redox shuttle, an all solid-state Z-scheme photocatalyst offers the potential of higher efficiency and is more amenable to fundamental investigations of atomic and electronic structure using surface science probes. Specifically, the experimental design involves working with systems that combine two metal oxide materials that act as oxidation and reduction photocatalysts that can be prepared both as a powder and as a thin film with well-defined surface properties. The transformational aspect of this research is in development of a new class of composite systems with potentially higher activity for hydrogen production as compared to any single catalyst. The development and characterization of the model photocatalyst presents many challenges, which this project addresses by an interdisciplinary approach with broad range of characterization techniques, solid-state synthesis, activity characterization and surface science tools. The project-related activities also expand the curriculum and cutting edge research opportunities in materials science and engineering with significant inclusion of underrepresented students. In addition, the educational part of the project introduces high school students and teachers to nanotechnology research using their newly developed photocatalytic testing kit. The project also includes several other innovative elements, such as the development of on-line educational tools designed to teach students the concepts of sustainable materials.

CBET - 1342028
There is growing interest in the development of nanocomposites consisting of organic polymers
and various nanomaterials. These new materials can provide unique functionalities as compared
to unmodified polymers in terms of dielectric, magnetic, thermal, mechanical, optical, transport,
permeation and separation properties. Although nanomaterials are considered potentially hazardous,
they are often considered safe when encapsulated into the matrix. However, systematic research
to confirm the abovementioned paradigm is lacking, despite the potential risks of nanomaterial
release to human health and environment.
Intellectual Merit :
Current research on the stability of nanocomposites has focused primarily on short term stability
and performance, whereas the longer term issues have not been properly addressed. This knowledge
gap has the potential to hinder both applications and acceptance of polymers in various industries.
More specifically, stability of both matrix and nanocomposites are of critical importance.
It is known that the polymer matrix can undergo degradation when exposed to various environmental
conditions during production, use and disposal. This can lead to nanofiller release, which
can potentially cause various health and environmental problems. Therefore, it is absolutely
critical to understand the behavior of nanocomposites under relevant environmental conditions.
More specifically, evaluation of the amounts and rates of Carbon Nanotubes (CNTs) release
from composites has been a tremendous challenge for the existing analytical techniques so
far. This project will utilize C-14 labeled CNTs which will allow us to quantify the released
CNTs using a relatively simple analytical technique. This will be of tremendous value for
advancing our knowledge of various CNTs exposure scenarios by developing accurate metrology
tools. This tool can be also vital for development of accurate life cycle assessments of CNTs
encapsulated into the polymer composites.
Broader Impacts :
This project can significantly impact nanotoxicology, environmental engineering, materials
science and green chemistry/engineering areas through evaluation of various strategies for
delivering functional nanocomposites with reduced health and environmental impacts. These
approaches are designed to make timely contributions to a basic understanding of the environmental
health and safety of nanotechnology. During the course of this project, the students will
gain fundamental and applied knowledge in many areas of science and engineering encompassing
environmental health and safety of nanotechnology. Our team has already utilized the resources
of a new NSF REU site in Nanotechnology for Health, Energy, and the Environment at Stony Brook
University. We will continue to recruit students through the REU site, which focuses on students
from non-research, 4-year institutions with this research project. Through several recruitment
mechanisms already established at the Stony Brook University we will reach underrepresented
groups, including students from minority and economically disadvantaged communities as well
as females. All these activities will establish a good foundation to achieve notable broader
impacts of this proposal

Currently, several aspects are missing in the current polymer or polymer composites based products. The first one is mechanical strength, which can be potentially improved by nanofillers. The second one is durability. The third one is sustainability, as replacing oil based polymers with sustainable filler produced from wood can reduce the need of using oil based products. This proposal aims at developing a new generation of high performance polymer composites with properties superior to the already existing solutions. It is going to create a very exciting opportunity of having the new generation of high performance sustainable nanofillers produced in substantial quantities.

Addressing the challenges related to traditional nanofillers while maintaining structural integrity of nanocomposites can be achieved by using sustainable bio-based nanofillers, such as surface modified Nano-Crystalline Cellulose (NCC). A development, optimization and commercializing of a novel process of making such materials is the basis of this proposal. Using nanocellulose as filler can be a very promising and scalable method of producing inexpensive 'green' composites. The proposed technology can be also very cost-efficient solution, given that USDA projections point out an extraordinary opportunity for this filler as nanocrystalline cellulose applications are expected to reach $600 billion mark by 2020 in the US alone.

Cement kilns are a significant contributor to anthropogenic nitrogen oxides emissions. This study seeks to demonstrate a promising and novel approach to the air pollution mitigation. A collaborative study will investigate an innovative approach to utilizing waste concrete material which, based on preliminary investigations, can economically and sustainably strip nitrogen dioxide from flue gas. The concrete waste containing sequestered pollutants can then be recycled as either set-accelerating or corrosion-inhibiting admixtures in new concrete. As a result, the approach can potentially turn waste materials into valuable products. The broader applications of the solution are not only in cement manufacturing, but also in incineration plants, boilers, process heaters, glass furnaces, and power plants. This project will be supported by an interdisciplinary team from Stony Brook and Clarkson Universities with highly complementary expertise in materials science, environmental chemistry and engineering, and civil engineering. The educational components of this project will focus on achieving the following objectives: (1) Expanding the undergraduate concentration in environmental engineering and chemistry; (2) Developing case studies that will allow students to grasp the fundamentals in environmental and civil engineering; (3) Increasing the number of underrepresented minority students who will be exposed to environmental chemistry, civil engineering and sustainability topics.

The technical approach to achieve the above mentioned outcomes will include several experimental strategies. The nitrogen dioxide absorption capacity of the demolished concrete as a function of particle size, age, type of aggregate, composition, moisture content and ambient relative humidity and temperature will be determined using state of the art experimental methods, including advanced spectroscopic techniques, reactor studies, and microscopy. Subsequently, the newly acquired properties of nitrogen dioxide sequestered concrete, such as set-accelerating and/or corrosion-inhibiting properties, will be analyzed for application in new concrete. More specifically, comprehensive studies focused on hydration kinetics, microstructure development, volumetric porosity, chloride binding capacity, chloride diffusion resistance, and corrosion rate will be conducted using various analytical techniques such as isothermal conduction calorimetry, nano-tomography, and potentiodynamic polarization. The intellectual merits of these approaches are in distinct novelties of the applications and characterization strategies. Moreover, this project will create new knowledge specifying mechanisms of nitrogen dioxide interaction with concrete surface, environmental conditions needed to maximize the uptake, the chemistry of the end products, and the potential utilization of the end products as constituents in new concrete.

PI: Orlov, Alexander
# 1604751

Nanomaterials and nanostructures are already revolutionizing many areas of the US manufacturing. Several composite products containing nanomaterials are also being introduced into a consumer market. However, developing new Nano products, while ensuring safety of consumers, is a very critical task to safeguard competitive and sustainable development of the US nanomanufacturing. The objective of this project is to address the knowledge gap in stability and rate of release of Carbon Nanotubes (CNTs) encapsulated in polymers under the influence of environmental factors. This information will be vital in designing stable and safe nanocomposites while reformulating the ones potentially posing the health risks.

Polymer materials reinforced with these nanomaterials are now at the verge of transforming many industries. These new nanocomposites benefit from many unique properties of CNTs, which can deliver extraordinary stiffness, reduction in weight, increased strength and resilience. Although CNTs are considered potentially hazardous, they are often viewed as safe when encapsulated into the polymer matrix. However, systematic research to confirm the abovementioned paradigm is lacking, despite the potential risks of released nanomaterials to human health and environment. Our preliminary data indicate that there is substantial degradation of CNTs -polymer composites due to exposure to environmental factors, especially UV radiation and moisture, leading to potential pathways for CNTs release. In the proposed research the PI will conduct a systematic study of stability of nanocomposites exposed to single and multiple environmental factors, while accurately quantifying the rates of nanomaterials release. A very distinct aspect of the proposed research is a comprehensive evaluation of nanocomposites in terms of their performance and functionality (mechanical testing), long term stability (environmental exposure and spectroscopic/microscopy characterization) and toxicity measurements. These three aspects will give an unprecedented level of detail to evaluate environmental and health risks of nanocomposites with the most promising functional properties.

This project will significantly impact nanotoxicology, environmental engineering, materials science and green chemistry/engineering areas through evaluation of various strategies for delivering functional nanocomposites with reduced health and environmental impacts. These approaches are designed to make timely contributions to a basic understanding of the environmental health and safety of nanotechnology. They will also make a notable contribution to ensuring the competitiveness of the US nanomanufacturing industry. During the course of this project students will gain fundamental and applied knowledge in many areas of science and engineering encompassing environmental health and safety of nanotechnology. By utilizing innovative on-line tools we will reach underrepresented groups, including students from minority and economically disadvantaged communities as well as females. All these activities will establish a good foundation to achieve notable broader impacts of this proposal.

Research examining modification of oxide surfaces with nanostructure has produced exciting materials for optical, mechanical, chemical, and other applications. These nanostructured surfaces can accelerate the chemical reactions used to produce fuel, enabling cheaper, more efficient, and more environmentally-sound production. As such, this project stands to protect the Nation's security through access to more affordable fuel sources. The project will advance understanding of how aspects of the nanostructured surface formation can facilitate the transformation of atmospheric emissions into fuels. This project also seeks to integrate research and educational activities through a combination of traditional and pioneering approaches. For example, the investigator plans to introduce educational games and on-line learning tools into undergraduate and high school courses. The effectiveness of efforts to broaden the participation of underrepresented groups in STEM will be evaluated through the on-line learning outcomes. Graduate students in the investigator's "Materials Impact on the Environment" course will have the opportunity to conduct pilot testing of self-cleaning catalytic coatings, which will be deposited on on-campus solar panels.

Traditional methods of controlling morphology and size distribution of nanoparticles have significant drawbacks. For instance, capping and encapsulating agents are usually difficult to remove, resulting in surface contamination, while physical deposition methods are challenging to scale up. This project offers a unique approach to forming nanostructured surfaces by establishing new structure-property relations, where particle size, metal-oxide interfaces, and shape are tuned by a relatively simple yet novel and scalable approach. Modulation of reduction temperature, concentration, type of dopants, and the presence of oxygen vacancies will enable control of particle size and morphology, which are critical for achieving unique catalytic properties. By combining new in-situ characterization techniques and theoretical methods based on machine learning tunable surfaces, capable of high conversion of carbon dioxide to fuels, will be developed.

This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.