Research team of Zhang Jinlong and Xing Mingyang, associate professor of East China University of science and technology: the size effect of platinum nanoparticles in photocatalytic reduction of carbon dioxide

With the development of human society, the global warming caused by excessive emission of carbon dioxide (CO2) is becoming increasingly significant, which has brought a huge threat to the natural environment and human survival Through photocatalytic reduction of CO2 (co2pr) to produce methane, methanol and other fuel molecules, not only can effectively alleviate the greenhouse effect brought by CO2, but also can convert solar energy into chemical energy to replace the traditional fossil energy, so it has attracted the attention of the whole world The results show that the activity of co2pr can be improved by loading Pt and other noble metal catalysts on the surface of photocatalyst Pt nanoparticles have strong oxidation resistance and excellent catalytic performance They are widely used as cocatalysts in co2pr reactions, providing a large number of electron traps and active sites for photocatalytic reduction In recent years, researchers have done a lot of research on the mechanism of Pt nanoparticles in photocatalytic reduction, but there is still a lack of systematic and in-depth study on the precise regulation of Pt nanoparticles and the structure-activity relationship between size effect and selective methane production by photoreduction of CO2 Recently, the research team of Professor Zhang Jinlong and associate professor Xing Mingyang of East China University of science and technology has made important progress in the research field of Pt nano particle size effect on selective methane production by photoreduction of CO2 (DOI: 10.1038 / s41467-018-03666-2) Prof Zhang Jinlong, male, Professor of East China University of science and technology, doctoral supervisor For four consecutive years, it has been selected into Elsevier Publishing Group's "list of highly cited scholars in China - Chemical Engineering" In 2001, he was awarded the title of the 7th dawn scholar of Shanghai; in 2004, he was selected into the New Century Excellent Talents funding program of the Ministry of education; in 2009, he was awarded the Shanghai Education Talent Award; in 2010, he enjoyed the special government allowance; in 2012, he was awarded the title of excellent academic leader and leading talents of Shanghai Professor Zhang Jinlong also won the first prize of 2017 Shanghai Natural Science Award, the second prize of 2011 national defense science and technology progress award of the Ministry of industry and information technology, the first prize of 2011 science and technology award of CNNC, the second prize of 2005 National Science and technology nominated by the Ministry of education, and the third prize of 2005 Shanghai Science and technology progress The main research fields are: (1) preparation of high-efficiency nano titanium dioxide photocatalyst and its application in environmental pollution control; (2) study on the interaction mechanism and photophysical and chemical properties of organic and inorganic host guest molecules in the micro environment reaction field; (3) preparation and characterization of functional membrane; (4) design and synthesis of organic functional dyes More than 360 SCI papers have been published in international first-class magazines such as chem., NAT Commun., chem Rev., chem SOC Rev., J am Chem SOC., angelw Chem Int ed., energy energy energy SCI., ACS Nano, etc., which have been cited more than 15000 times, and the "h-index" is 63 18 papers with high ESI citations and 3 articles with 0.1% hot topics were selected He is also deputy editor in chief of res chem INTERMED., international journal, SCI Rep., appl Catalyst B: environ., International Editorial Committee of dyes and segments, guest editor in chief of Inter J photoenergy, guest editor in chief of J nanotechnology, and Editorial Committee of photosensitive science and photochemistry Introduction to associate professor Xing Mingyang, male, Ph.D., associate professor of East China University of science and technology, winner of "young scientist" project of national key R & D plan (former Youth "973"); Shanghai "Pujiang scholar", "morninglight scholar"; young member of photocatalysis Professional Committee of China Photographic society; won the first prize of 2017 Shanghai Natural Science Award The main research fields are as follows: (1) advanced oxidation technologies (AOPs) such as photocatalytic synergetic Fenton reaction for the treatment of refractory organic pollutant wastewater; (2) photocatalytic reduction of CO2; (3) photodegradation of aquatic hydrogen So far, 68 SCI papers have been published and cited for 3348 times, and the "h-index" is 31 As the first or corresponding author in Chem., NAT Commun., chem SOC Rev., J am Chem SOC., angel Chem Int ed., adv funct Mater., J photo Photobiol C., mater Horiz., small, 48 SCI papers were published in international journals such as appl Catalyst B, 5 papers were selected as "highly cited papers of ESI", 2 papers were selected as "0.1% hot articles", 2 papers were selected as journal cover papers, 4 invention patents were authorized, and 2 English Monographs (wily book, Springer book) were edited Cutting edge research achievements: the size effect of platinum nanoparticles on the activity and selectivity of photocatalytic reduction of carbon dioxide Professor Zhang Jinlong and associate professor Xing Mingyang of East China University of science and technology have made a series of significant research progress in the research of selective methane production by photocatalytic reduction of carbon dioxide Through fluorination and hydrophobic modification on the surface of the composite semiconductor, the competitive adsorption of CO 2 on the catalyst surface was improved, and the conversion of CO 2 to methane was promoted dynamically The yield of methane was increased by 24 times (J Phys Chem Lett., 2016, 7, 2962) For example, the space separation of electrons and holes can be realized by loading electron trapping agent Pt and hole trapping agent coo x outside and inside the pore framework respectively By means of fluorescence and photocurrent tests, it is found that the charge space separation effect is conducive to prolonging the lifetime of electrons and holes, so that the yield of methane generated by photoreduction of CO2 increases from 0.15 μ mol g-1h-1 to 9.3 μ mol g-1h-1, and the selectivity increases from 35.7% to 72.1% (mater Horiz, 2016, 3, 608; nanotechnology, 2018, 29, 154005) However, for the photocatalytic reduction of CO2 Based on gas-solid reaction, it is still a big challenge to improve the methane production and selectivity without sacrificial agent The introduction of Pt and other Co catalysts plays an important role in improving the efficiency of photocatalytic reduction of CO2 Therefore, it is of great scientific significance to study the structure-activity relationship between Pt size effect and photoreduction of CO2 For the first time, the team systematically studied the structure-activity relationship between Pt size effect and selective methane production by photoreduction of CO2 First of all, the method of "acid base mediated alcohol reduction (abar)" was used to realize the precise regulation of Pt nanoparticles size (1.8nm-7.0nm) on the catalyst surface without introducing organic impurities such as PVP Combined with X-ray photoelectron spectroscopy (XPS), femtosecond transient absorption spectroscopy (FS TA) and other characterization methods, the differences in geometric characteristics and electronic properties of Pt nanoparticles with different sizes were analyzed The influence of size effect of Pt nanoparticles on reaction activity and product selectivity in co2pr was systematically investigated The "trace / facet" exposed by Pt nanoparticles was demonstrated ”The site is the active site of selective methanogenesis (Fig 1a, b) Reducing the size of Pt nanoparticles can promote the charge transfer efficiency in the photocatalytic reaction and enhance the activity of co2pr (methane: 9.7 μ mol g-1h-1) and competitive hydrogen evolution reaction (her), but it will reduce the selectivity of methane (39.1%) The experimental results and DFT calculation show that the "trace / facet" site on the surface of Pt nanoparticles is the active site of methanogenesis, and the low coordination sites exposed on the surface are more conducive to the occurrence of her With the increase of the size of Pt nanoparticles, the proportion of "trace / facet" active sites exposed by Pt nanoparticles increases gradually, the yields of methane (1.1 μ mol g-1h-1) and hydrogen will be greatly reduced, but the degree of reduction of hydrogen is greater, making the selectivity of methane increase (79.1%) Therefore, it is concluded that it is difficult to improve the yield and selectivity of methane at the same time by adjusting the size of Pt nanoparticles, that is to say, "fish and bear paw cannot have both" Fig 1 The "trace / facet" site exposed by Pt nanoparticles is the active site of selective methanogenesis (source: Nat Commin) In order to achieve the "fish and bear paw" in the photoreduction of CO2 reaction, we must find a way to selectively passivate the hydrogen production active site exposed by small-sized Pt nanoparticles, that is, to passivate the "corner" and "edge" sites with low coordination The general solution is to selectively load "passivator" on these sites by using the difference of surface energy However, the traditional nano synthesis technology selectively passivates the "corner" and "edge" sites at the micro scale of 1 ~ 2 nm, which is not only lack of mature load technology, but also lack of effective characterization means to verify the accuracy and effectiveness of the micro scale load In order to solve this problem, the team adopted the ingenious method of "selective adsorption and passivation of surface active sites", that is, taking advantage of the characteristics of Pt surface which is easy to adsorb CO molecules to produce catalytic poisoning, through the small size (1.8 Nm) Pt nanoparticles selectively adsorbed CO molecules at the sites of "corner" and "edge" to achieve the passivation of the side reaction of hydrogen production, while the exposed sites of "terrace / facet" did not adsorb CO to continue methane production, achieving the yield (17.3 μ mol g-1 h-1) and selectivity (62.9%) of photoreductive CO 2 methane production at the same time (Fig 2 C-E) Figure 2 "Selective adsorption and passivation of surface active sites" improves the yield and selectivity of photoreductive CO 2 methane production at the same time (source: Nat Commun) This achievement was published in nature communications (NAT Commun., 2018, 9, 1252) It was completed by Dong Chunyang, a doctoral candidate, under the guidance of Professor Zhang Jinlong and associate professor Xing Mingyang This work has also been greatly supported by Dr Lian Cheng and Professor Liu honglai in the theoretical calculation of dynamics, and by Professor Li Mingde from Shantou University in the measurement of femtosecond transient absorption spectrum This work has been supported by the national key research and development plan youth project and the National Natural Science Foundation and other projects Nowadays, people and scientific research have been paid more and more attention in the economic life China has ushered in the "node of science and technology explosion" Behind the progress of science and technology is the work of countless scientists In the field of chemistry, in the context of the pursuit of innovation driven, international cooperation has been strengthened, the influence of Returned Scholars in the field of R & D has become increasingly prominent, and many excellent research groups have emerged in China For this reason, CBG information adopts the 1 + X reporting mechanism CBG information, chembeango app, chembeango official microblog, CBG wechat subscription number and other platforms jointly launch the column of "people 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