02461nas a2200253   4500008004100000022001400041245017300055210006900228260000900297300001600306490000600322520151900328653002801847653001801875653001401893653001901907653002501926100002101951700002701972700002301999700002502022700003002047856013002077       2021                        eng d  a2574-096200aAqueous methanol to formaldehyde and hydrogen on Pd/TiO2 by photocatalysis in direct sunlight: structure dependent activity of nano-Pd and atomic Pt-coated counterparts0 aAqueous methanol to formaldehyde and hydrogen on PdTiO2 by photo  cNOV   a13347-133600 v43 aIn the present investigation, facet-controlled Pd nanoparticles with nanocube (Pd-NC) and truncated octahedron (Pd-TO) morphologies, and their counterparts with half-a-monolayer of atomic Pt coated (0.5 theta(Pt)-Pd-NC and 0.5 theta(Pt)-Pd-TO) surfaces were prepared. All of them were characterized and evaluated as cocatalyst after supporting them on commercial titania (P25) (Pd-NC/P25, Pd-TO/P25, 0.5 theta(Pt)-Pd-NC/P25, and 0.5 theta(Pt)-Pd-TO/P25) under direct sunlight and/or one sun conditions for the oxidation of methanol to formaldehyde along with solar hydrogen production. Pd-NC/P25 shows higher activity for hydrogen generation compared to Pd-TO/P25; however, activity reversal occurs with the above cocatalysts, but, after Pt-coating with further enhanced activity. The highest conversion of methanol (0.2 mu mol/h.mg) to 100% selective formaldehyde was observed with 0.5 theta(Pt)-Pd-TO/P25, while other catalysts show significantly lower methanol conversion in the following order: 0.5 theta(Pt)-Pd-TO/P25 > 0.5 theta(Pt)-Pd-NC/P25 > Pd-NC/P25 > Pd-TO/P25. Pt-coated on (111) facets of Pd-TO simulates the activity associated as that of Pt(111) facets and demonstrating the highest and facet dependent activity. The present study is truly in resonance with exploiting the surface properties for heterogeneous catalysis, and highlights that less than a monolayer of Pt is sufficient to simulate the activity as that of bulk Pt. It is worth exploring this concept to other metals and substrates too.10aheterogeneous catalysis10aNanomaterials10aOxidation10aPhotocatalysis10asurface modification1 aNalajala, Naresh1 aSalgaonkar, Kranti, N.1 aChauhan, Inderjeet1 aMekala, Siva, Prasad1 aGopinath, Chinnakonda, S.  uhttps://library.ncl.res.in/content/aqueous-methanol-formaldehyde-and-hydrogen-pdtio2-photocatalysis-direct-sunlight-structure02917nas a2200229   4500008004100000022001400041245015400055210006900209260000900278300001600287490000700303520206700310100002702377700002102404700002302425700002102448700002302469700002002492700001802512700003002530856012702560       2023                        eng d  a2050-748800aBaby step in assembling and integrating the components of an artificial photosynthesis device with forced heterojunctions towards improved efficiency0 aBaby step in assembling and integrating the components of an art  cJUL   a15168-151820 v113 a<p>
	How to achieve unassisted, economical, scalable, and sustainable artificial photosynthesis for liquid fuels/products with improved solar-to-fuel efficiency (STFE) to address a carbon-neutral economy remains a big question. To a large degree, the extent of charge separation at heterojunction interfaces and charge utilization determine the STFE. Towards this, BiVO3 is assembled from ionic-precursors into TiO2 pores, and integrated structurally and electronically with TiO2 on calcination as BiVO4 quantum dots (BVQDs). BVQDs in TiO2 (BVT) pores lead to an all-inorganic system with a sub-quadrillion number of heterojunctions in a 1 cm(2) device (contains similar to 25 mu g of BiVO4 (similar to 2.5 wt%) in the nanopores of similar to 975 mu g of TiO2 (similar to 97.5 wt%)) and facilitate artificial photosynthesis. We demonstrate 31-38% STFE with a photon to chemical conversion turn over frequency (ToF(P2C)) of 2.73 s(-1) with a 1 cm(2) wireless BiVO4-TiO2 artificial leaf (BVT-AL) device for HCHO and CH3OH. The sequential nature of CO2 reduction to HCHO and then to CH3OH is evident from the reaction results. (CO2)-C-13 isotopic labeling experiments confirm that the input CO2 is the source for product formation. A large increase in the photocurrent density and incident photon-to-current efficiency (IPCE) of BVT, over 100% for the BiVO4 photoanode in visible light, demonstrates and supports efficient visible light absorption, charge separation and migration to the redox sites. A device has been demonstrated to show sustainable activity in direct sunlight, and addresses scalability from 1 to 9 cm(2). Assuming no change (50% decrease) in the STFE, a 6.74 m(2) device is expected to convert 1 (0.5) kg h(-1) CO2 into C1-oxygenates in sunlight. DFT calculations carried out with anatase TiO2 (101) and BiVO4 (121) interfaces support many of the experimental findings, including electron flow from the latter to the former, and interaction of the oxygen of TiO2 with BiVO4 and vice versa at the interface towards forced heterojunctions.</p>
1 aSalgaonkar, Kranti, N.1 aBajpai, Himanshu1 aMhamane, Nitin, B.1 aNalajala, Naresh1 aChauhan, Inderjeet1 aThakkar, Kavita1 aJoshi, Kavita1 aGopinath, Chinnakonda, S.  uhttps://library.ncl.res.in/content/baby-step-assembling-and-integrating-components-artificial-photosynthesis-device-forced02217nas a2200205   4500008004100000022001400041245012900055210006900184260000800253300001400261490000700275520145200282100002301734700002801757700002101785700002301806700002701829700003001856856012501886       2023                        eng d  a1477-922600aNanostructured Co-doped BiVO4 for efficient and sustainable photoelectrochemical chlorine evolution from simulated sea-water0 aNanostructured Codoped BiVO4 for efficient and sustainable photo  cFEB  a2051-20610 v523 a<p>
	The co-production of hydrogen and chlorine from sea-water splitting could be a potential, sustainable and attractive route by any method. However, challenges to overcome are many, and critically, the sustainability and operating potential of the electrocatalyst are important. In this work, we report on Co-doping in the BiVO4 (Co-BV) crystal lattice and employed the same as the photoanode; Co-BV exhibits a photocurrent of 190 mu A cm(-2) at 1.1 V vs. RHE (the reversible hydrogen electrode) in the acidic sodium chloride solution (pH 2.3) under one sun illumination. The best-performing photoanode, with 0.05 mol% of Co doping (0.05 Co-BV), selectively produced active chlorine with 92% faradaic efficiency at 1.1 V vs. RHE by successfully suppressing the kinetically sluggish oxygen evolution reaction (OER) and the stability of the catalyst was demonstrated for up to 20 h. This is the lowest operating potential reported for the chlorine evolution reaction (CER), thus far. The overpotential required for CER with 0.05 Co-BV is lower than that of OER, which leads to selective CER at 1.1 V (vs. RHE). Co-doping into the BiVO4 lattice decreases the charge transfer resistance and enhances the CER kinetics due to its structural and electronic integration with the BV lattice. We demonstrate that Co-doping also improves the lifetime of the charge carrier and enhances the current density of CER and sustainability of the catalyst.</p>
1 aChauhan, Inderjeet1 aPatra, Kshirodra, Kumar1 aBajpai, Himanshu1 aMhamane, Nitin, B.1 aSalgaonkar, Kranti, N.1 aGopinath, Chinnakonda, S.  uhttps://library.ncl.res.in/content/nanostructured-co-doped-bivo4-efficient-and-sustainable-photoelectrochemical-chlorine02213nas a2200241   4500008004100000022001400041245018400055210006900239260000800308490000700316520131500323653002201638653001801660653001401678653001901692653001901711100002701730700002101757700002101778700002001799700003001819856012201849       2023                        eng d  a1861-472800aSelective and generic photocatalytic oxidation of alcohol with Pd-TiO2 thin films: butanols to butanal/butanone with different morphologies of Pd and 0.5 theta(Pt)-Pd counterparts0 aSelective and generic photocatalytic oxidation of alcohol with P  cMAR0 v183 a<p>The present study reports on the photocatalytic oxidation of butanols to butanal/butanone using thin film form of facet-dependent nano-Pd supported on commercial TiO2 under one-sun condition and demonstrates the generic nature. Pd-nanocube (Pd-NC(100)), Pd-truncated octahedron (Pd-TO (100) and (111)), polycrystalline (Pd-PC), and their counterparts with half-a-monolayer Pt-coated on Pd (0.5 theta(Pt)-Pd)) have been used as co-catalyst. A potentially scalable thin film form of Pd/TiO2 photocatalyst, prepared by drop-casting method, has been employed to study oxidation of n-butanol, 2-butanol, and iso-butanol to corresponding aldehyde/ketone. 100% selectivity is demonstrated to respective aldehyde/ketone with any catalyst used in the present study with varying degree of butanols conversion by NMR. 0.5 theta(Pt)-Pd-TO/TiO2 shows the highest conversion of 2-butanol to butanone (13.6% in 4 h). Continuous 10 h of reaction with the most active 0.5 theta(Pt)-Pd-TO/P25 catalyst demonstrates 31% conversion of 2-butanol to butanone, and catalyst recyclability has been demonstrated. The present protocol can be scalable to large scales to maximize the conversion in direct sunlight. Due to its generic nature, the current method can also be applied to many other alcohols and substrate molecules.</p>
10aenergy conversion10aNanomaterials10aOxidation10aPhotocatalysis10aSustainability1 aSalgaonkar, Kranti, N.1 aKale, Sandip, R.1 aNalajala, Naresh1 aMansuri, Sayana1 aGopinath, Chinnakonda, S.  uhttps://library.ncl.res.in/content/selective-and-generic-photocatalytic-oxidation-alcohol-pd-tio2-thin-films-butanols05784nas a2200325   4500008004100000245013700041210006900178260000800247300001400255490000600269520469500275100002204970700002304992700002005015700001905035700001805054700002005072700001705092700001705109700002105126700002305147700001605170700002705186700001805213700002705231700002205258700002405280700002405304856013005328       2024                        eng d00aLead-free Cs2AgBiCl6 double perovskite: experimental and theoretical insights into the self-trapping for optoelectronic applications0 aLeadfree Cs2AgBiCl6 double perovskite experimental and theoretic  cJUL  a476–4890 v43 a<p>
	<span style="color: rgb(21, 21, 21); font-family: Roboto, arial, sans-serif; font-size: 16px;">Lead-free double perovskites (DPs) will emerge as viable and environmentally safe substitutes for Pb-halide perovskites, demonstrating stability and nontoxicity if their optoelectronic property is greatly improved. Doping has been experimentally validated as a powerful tool for enhancing optoelectronic properties and concurrently reducing the defect state density in DP materials. Fundamental understanding of the optical properties of DPs, particularly the self-trapped exciton (STEs) dynamics, plays a critical role in a range of optoelectronic applications. Our study investigates how Fe doping influences the structural and optical properties of Cs</span><span style="box-sizing: border-box; outline: none; line-height: 0; position: relative; vertical-align: baseline; bottom: -0.25em; color: rgb(21, 21, 21); font-family: Roboto, arial, sans-serif;">2</span><span style="color: rgb(21, 21, 21); font-family: Roboto, arial, sans-serif; font-size: 16px;">AgBiCl</span><span style="box-sizing: border-box; outline: none; line-height: 0; position: relative; vertical-align: baseline; bottom: -0.25em; color: rgb(21, 21, 21); font-family: Roboto, arial, sans-serif;">6</span><span style="color: rgb(21, 21, 21); font-family: Roboto, arial, sans-serif; font-size: 16px;">&nbsp;DPs by understanding their STEs dynamics, which is currently lacking in the literature. A combined experimental–computational approach is employed to investigate the optoelectronic properties of pure and doped Cs</span><span style="box-sizing: border-box; outline: none; line-height: 0; position: relative; vertical-align: baseline; bottom: -0.25em; color: rgb(21, 21, 21); font-family: Roboto, arial, sans-serif;">2</span><span style="color: rgb(21, 21, 21); font-family: Roboto, arial, sans-serif; font-size: 16px;">AgBiCl</span><span style="box-sizing: border-box; outline: none; line-height: 0; position: relative; vertical-align: baseline; bottom: -0.25em; color: rgb(21, 21, 21); font-family: Roboto, arial, sans-serif;">6</span><span style="color: rgb(21, 21, 21); font-family: Roboto, arial, sans-serif; font-size: 16px;">&nbsp;(Fe–Cs</span><span style="box-sizing: border-box; outline: none; line-height: 0; position: relative; vertical-align: baseline; bottom: -0.25em; color: rgb(21, 21, 21); font-family: Roboto, arial, sans-serif;">2</span><span style="color: rgb(21, 21, 21); font-family: Roboto, arial, sans-serif; font-size: 16px;">AgBiCl</span><span style="box-sizing: border-box; outline: none; line-height: 0; position: relative; vertical-align: baseline; bottom: -0.25em; color: rgb(21, 21, 21); font-family: Roboto, arial, sans-serif;">6</span><span style="color: rgb(21, 21, 21); font-family: Roboto, arial, sans-serif; font-size: 16px;">) perovskites. Successful incorporation of Fe</span><span style="box-sizing: border-box; outline: none; line-height: 0; position: relative; vertical-align: baseline; top: -0.5em; color: rgb(21, 21, 21); font-family: Roboto, arial, sans-serif;">3+</span><span style="color: rgb(21, 21, 21); font-family: Roboto, arial, sans-serif; font-size: 16px;">&nbsp;ions is confirmed by X-ray diffraction and Raman spectroscopy. Moreover, the Fe–Cs</span><span style="box-sizing: border-box; outline: none; line-height: 0; position: relative; vertical-align: baseline; bottom: -0.25em; color: rgb(21, 21, 21); font-family: Roboto, arial, sans-serif;">2</span><span style="color: rgb(21, 21, 21); font-family: Roboto, arial, sans-serif; font-size: 16px;">AgBiCl</span><span style="box-sizing: border-box; outline: none; line-height: 0; position: relative; vertical-align: baseline; bottom: -0.25em; color: rgb(21, 21, 21); font-family: Roboto, arial, sans-serif;">6</span><span style="color: rgb(21, 21, 21); font-family: Roboto, arial, sans-serif; font-size: 16px;">&nbsp;DPs exhibit strong absorption from below 400 nm up to 700 nm, indicating sub-band gap state transitions originating from surface defects. Photoluminescence (PL) analysis demonstrates a significant enhancement in the PL intensity, attributed to an increased radiative recombination rate and higher STE density. The radiative kinetics and average lifetime are investigated by the time-resolved PL (TRPL) method; in addition, temperature-dependent PL measurements provide valuable insights into activation energy and exciton–phonon coupling strength. Our findings will not only deepen our understanding of charge carrier dynamics associated with STEs but also pave the way for the design of some promising perovskite materials for use in optoelectronics and photocatalysis.</span></p>
1 aRahane, Swati, N.1 aRahane, Ganesh, K.1 aMandal, Animesh1 aJadhav, Yogesh1 aGodha, Akshat1 aRokade, Avinash1 aShah, Shruti1 aHase, Yogesh1 aWaghmare, Ashish1 aSaykar, Nilesh, G.1 aRoy, Anurag1 aSalgaonkar, Kranti, N.1 aDubal, Deepak1 aMakineni, Surendra, K.1 aDzade, Nelson, Y.1 aJadkar, Sandesh, R.1 aRondiya, Sachin, R.  uhttps://library.ncl.res.in/content/lead-free-cs2agbicl6-double-perovskite-experimental-and-theoretical-insights-self-trapping02728nas a2200193   4500008004100000022001400041245019700055210006900252260000800321300001600329490000700345520193100352100002202283700002702305700001802332700003002350700002702380856012702407       2025                        eng d  a2040-336400aEnhanced mid-visible light absorption and long-lived charge carriers in an electronically and structurally integrated BiVO4-TiO2 photoanode for efficient artificial photosynthesis applications0 aEnhanced midvisible light absorption and longlived charge carrie  cMAY  a12738-127500 v173 a<p>
	The ever-increasing demand for sustainable solutions for eliminating environmental pollutants, solar energy harvesting, water splitting, etc. have led to the design and development of novel materials to achieve the desired result. In this regard, structurally and electronically integrated (SEI) BiVO4-TiO2 (SEI-BVT) with abundant heterojunctions has emerged as a promising entity for efficient charge separation, which in turn enhances artificial photosynthesis (APS) activity. The present work adopted a unique synthetic strategy using SILAR to fabricate SEI-BVT from ionic precursors (Bi3+ and VO43-) into the pores of TiO2, exhibiting benchmark APS efficiency compared to the individual components. This preparation results in approximately 180 trillion uniformly distributed heterojunctions in 1 mg cm-2 of the SEI-BVT photoanode material. Charge carriers in SEI-BVT and BiVO4 are similar; however, the recombination is highly hindered when SEI-BVT heterojunctions are formed in the former. Our earlier work demonstrated 31-38% solar-to-fuel efficiency (STFE) with BiVO4-TiO2 for APS in the presence of the Pd-nanocube co-catalyst. The emphasis of the current work is to explore the dynamics of the light-induced processes in these heterojunctions to understand the interfacial charge transfer process. Femtosecond transient absorption (TA) spectroscopy has been employed to monitor the excited state dynamics. Our results show that new trap states have evolved under light illumination, which are significantly long-lived and hinder charge recombination, and consequently enhance STFE. A significantly large number of charge carriers exhibit a lifetime of &gt;&gt; 6 ns with visible light photons, at least up to 720 nm, which is higher than the band-gap absorption onset at 490 nm for SEI-BVT compared to bulk BiVO4. The rate of formation of charge carriers is significantly affected in the heterojunctions.</p>
1 aJha, Vikas, Kumar1 aSalgaonkar, Kranti, N.1 aSaha, Avishek1 aGopinath, Chinnakonda, S.1 aIyer, Siva, Subramania  uhttps://library.ncl.res.in/content/enhanced-mid-visible-light-absorption-and-long-lived-charge-carriers-electronically-and02326nas a2200277   4500008004100000022001400041245012700055210006900182260000800251490000700259520134800266653002301614653002601637653002401663653001901687653001201706100002001718700002701738700002901765700002401794700002301818700002801841700003001869700001801899856013101917       2025                        eng d  a1861-472800aSynthesis of Pd-integrated carbon Dot@TiO2 thin film for photocatalytic glycerol reforming reaction for producing hydrogen0 aSynthesis of Pdintegrated carbon DotTiO2 thin film for photocata  cNOV0 v203 a<p>
	A series of thin-film photocatalysts comprising TiO2 modified with carbon dots (CDs) dispersed either with palladium (Pd-CD/TiO2) or nickel (Ni-CD/TiO2) were synthesized via solid-state and wet-impregnation methods. Morphological characterization (HR-TEM, SEM-EDS) confirmed the anatase phase of TiO2 and the atomic dispersion of metal-integrated CDs on its surface. UV-vis DRS and XPS analyses revealed a marginal red shift in band-gap and the presence of sp2-hybridized graphitic carbon, and metal-carbon interactions, indicating enhanced light absorption and charge separation through Schottky junctions. Under direct sunlight illumination, Pd-CD/TiO2 thin film exhibited superior hydrogen yield (1167 mu mol g-1 h-1) and maintained stability over 25 h, outperforming Ni-CD/TiO2 (494 mu mol g-1 h-1) and bare TiO2 (166 mu mol g-1 h-1) photocatalyst thin films. Concurrent glycerol oxidation at neutral pH (pH similar to 7) yields glycolaldehyde (41% selectivity), formic acid, and dihydroxyacetone as value-added products. Enhanced photocurrent density and lower impedance of Pd-CD/TiO2 corroborate improved charge carrier separation and dynamics. The results demonstrate that Pd-CD synergistically improves the photocatalytic performance of the Pd-CD/TiO2 for sustainable hydrogen generation and selective biomass valorization.</p>
10aGlycerol oxidation10aGraphitic carbon dots10ahydrogen production10aPhotocatalysis10atitania1 aAbraham, Athira1 aSalgaonkar, Kranti, N.1 aNivedhitha, Thazhath, R.1 aEkal, Vishal, Ashok1 aKondhekar, Deepali1 aChakraborty, Shubhankar1 aGopinath, Chinnakonda, S.1 aSaha, Avishek  uhttps://library.ncl.res.in/content/synthesis-pd-integrated-carbon-dottio2-thin-film-photocatalytic-glycerol-reforming-reaction02423nas a2200217   4500008004100000022001400041245011600055210006900171260000800240300001400248490000600262520161300268100002801881700002601909700002801935700002101963700002701984700003402011700003002045856013002075       2025                        eng d  a2398-490200aUtilizing nature's endowment: artificial leaf concept for methane activation to C-C coupled ethanol or ethylene0 aUtilizing natures endowment artificial leaf concept for methane   cDEC  a6798-68100 v93 a<p>
	Methane activation (MA) to platform chemicals under ambient conditions still remains an open challenge to be fully realised. The present work shows the fabrication of CeVO4 quantum dots (CV-QDs) by a bottom-up approach; they are assembled from Ce3+ and metavanadate ions, and structurally and electronically integrated into the micro-/meso-pores of TiO2 (CV-QD-TiO2 (CVT)), demonstrating the conversion of MA to ethanol/ethylene by visible light-driven photocatalysis. CV-QDs in confined pores modify the quantum confinement effects and are characterized by physicochemical methods. The current synthetic strategy is potentially scalable and results in sub-quadrillion heterojunctions in a 1 mg CVT photoanode spread over 1 cm2. MA with CVT under one-sun conditions demonstrates similar to 100% selectivity to ethanol, yielding 4.36 mu mol h-1 cm-2, with a solar-to-fuel efficiency (STFE) of 0.56. Further, by employing a co-catalyst, significant STFE (5.08) and yield (39.5 mu mol h-1 cm-2) are achieved selectively towards ethylene. A deliberate addition of methanol increases the rate of ethanol production by 17.2 times, indicating that the methyl-methoxy interaction is the origin of C-C coupling. Weight is normalized to a gram of CV-QDs in a large area CVT photoanode to yield 109 mmol h-1 gCV-QD-1 of ethanol and 988 mmol h-1 gCV-QD-1 of ethylene. Enhanced activity and selectivity towards the C2-product is attributed to band-edge modulation and trillions of heterojunctions, which in turn facilitate charge separation and charge transfer for effective charge utilisation at redox sites.</p>
1 aKanungo, Subhashree, S.1 aMishra, Abhaya, Kumar1 aAvani, Mangaladasan, J.1 aBajpai, Himanshu1 aSalgaonkar, Kranti, N.1 aJavaregowda, Bharathkumar, H.1 aGopinath, Chinnakonda, S.  uhttps://library.ncl.res.in/content/utilizing-natures-endowment-artificial-leaf-concept-methane-activation-c-c-coupled-ethanol02265nas a2200229   4500008004100000022001400041245011600055210006900171260000800240490000700248520145100255653002201706653001901728653001901747653002101766653001701787100002901804700002701833700001801860700003001878856012701908       2025                        eng d  a1867-388000aVisible-light-driven photocatalytic glycerol oxidation to value-added and highly selective glyceric/lactic acid0 aVisiblelightdriven photocatalytic glycerol oxidation to valueadd  cSEP0 v173 a<p>
	Achieving economical and sustainable artificial photosynthesis (APS) in direct sunlight for liquid fuel production with high efficiency remains an important challenge. A major obstacle in the photoelectrochemical (PEC) oxidation of organic compounds is attaining high selectivity with the desired product(s). This study introduces a novel strategy by integrating BiVO4 quantum dots (BVQDs), structurally and electronically, into the nanopores of commercial TiO2 (BVT for BVQDs integrated in pores of TiO2) to improve solar-driven photocatalysis. The band gap of the BVT photoanode decreases to 2.53 eV as compared to pure TiO2 (3.2 eV), which enhances visible light absorption and charge separation. BVT with Pt as a co-catalyst acts as an APS system, which selectively oxidizes glycerol into lactic acid (100% selectivity at 1 mM glycerol) and glyceric acid (98% selectivity at 100 mM), while simultaneously generating green hydrogen. Selectivity of the product can be further controlled by anaerobic or aerobic conditions as well as the length of the reaction time. Direct integration of BVQDs into TiO2 mesopores significantly enhances charge separation as well as utilization at redox sites. Current work provides key insights into optimizing photocatalytic conditions for highly selective value-added chemical production, which highlights the sustainability and efficacy of TiO2-based semiconductors with quantum dot integration.</p>
10aenergy conversion10aEnergy storage10aPhotocatalysis10aQuantum material10asolar energy1 aKulkarni-Sambhare, Mukta1 aSalgaonkar, Kranti, N.1 aSaha, Avishek1 aGopinath, Chinnakonda, S.  uhttps://library.ncl.res.in/content/visible-light-driven-photocatalytic-glycerol-oxidation-value-added-and-highly-selective