02443nas a2200265   4500008004100000022001400041245016400055210006900219260000900288300001400297490000600311520153400317653001101851653002301862653001501885653001801900653001901918653002001937100001701957700001901974700001801993700002102011700001802032856012702050       2019                        eng d  a2168-048500aDirect thermal polymerization approach to N-rich holey carbon nitride nanosheets and their promising photocatalytic H-2 evolution and charge-storage activities0 aDirect thermal polymerization approach to Nrich holey carbon nit  cMAY   a9428-94380 v73 a<p>Energy conversion and energy storage are two crucial challenges in green chemistry that have attracted tremendous attention for the last several decades. In this work, we have addressed both issues by synthesizing nitrogen-rich, few-layer-thick holey graphitic carbon nitride (g-C3N4) nanosheets by a simple, novel, direct thermal polymerization method, which is found to be very good in photocatalytic H-2 evolution reaction (energy-conversion) and charge-storage supercapacitor (energy-storage) applications. This as-synthesized conjugated polymer semiconductor (obtained stoichiometry C3N4.8) with unique structural and morphological advantages exhibits superior photocatalytic water splitting activity to H-2 evolution (2 620 mu mol h(-1) g(-1)) without the help of any cocatalysts under visible light in the presence of 20% triethanolamine (TEOA). The calculated apparent quantum yield is 8.5% at 427 nm, and the rate of photocatalytic hydrogen generation remained constant for nine consecutive catalytic cycles (9 h photocatalysis). The present material also shows electrochemical double layer capacitor (EDLC) behavior in alkaline electrolyte, where a symmetric coin cell device consisting of this electrode material without any large area support or conductive filler delivers high specific capacitance (275 F g(-1)), energy density (30 Wh kg(-1)), and power density (6651 W kg(-1)), and the supercapacitor cell can retain &gt;98% capacitance efficiency up to 10 000 measured cycles at various current densities.</p>
10ag-C3N410aHydrogen evolution10ananosheets10aPhotocatalyst10asupercapacitor10awater splitting1 aAntil, Bindu1 aKumar, Lakshya1 aReddy, K., P.1 aGopinath, C., S.1 aDeka, Sasanka  uhttps://library.ncl.res.in/content/direct-thermal-polymerization-approach-n-rich-holey-carbon-nitride-nanosheets-and-their02344nas a2200181   4500008004100000022001400041245017700055210006900232260000800301300001600309490000600325520161800331100001701949700001701966700003001983700001802013856013102031       2020                        eng d  a2050-748800aDirected holey and ordered g-C(3)N(4.5)nanosheets by a hard template nanocasting approach for sustainable visible-light hydrogen evolution with prominent quantum efficiency0 aDirected holey and ordered gC3N45nanosheets by a hard template n  cJUL  a13328-133390 v83 a<p>It is desirable yet challenging to synthesize a highly ordered holey carbon nitride material with excess nitrogen atoms for a sustainable solar H(2)evolution. Herein, we report the development of directed highly ordered nitrogen-rich honeycomb-like mesoporous carbon nitride nanosheets by using a novel synthetic approach for this purpose. The unique formation route, surface structure and charge carrier dynamics of the two dimensional holey nanosheets are comprehensively monitored and confirmed by SAXS, HRTEM, AFM, BET, XPS and TRPL analyses. Non-stoichiometric high nitrogen content mesoporous nanosheets with the final stoichiometry of g-C(3)N(4.5)acquiring a high specific surface area (382 m(2)g(-1)), remarkable pore size (7.2 nm) and sheet thickness similar to 5-6 nm are realized in this first report. This elegant material possesses unique low band-gap energy (2.42 eV). Remarkably, the as-synthesized g-C(3)N(4.5)NSs exhibit a record high photocatalytic H(2)evolution rate of 8180 mu mol g(-1)h(-1)under the present light irradiation (420 &lt;=lambda &lt;= 510 nm) condition. The apparent quantum efficiency is found to be as high as 27.14% at 420 nm and retains its photocatalytic activity for longer consecutive catalytic cycles. Bigger pore size and pore volume, and thin walls leading to shortening of the path length of exciton pairs, efficient charge separation and the prolonged average life time of the charge carriers, and lone electron pairs associated with the excess nitrogen content are found to be the reasons behind the excellent visible light driven water splitting reaction.</p>
1 aAntil, Bindu1 aRanjan, Ravi1 aGopinath, Chinnakonda, S.1 aDeka, Sasanka  uhttps://library.ncl.res.in/content/directed-holey-and-ordered-g-c3n45nanosheets-hard-template-nanocasting-approach-sustainable02731nas a2200277   4500008004100000022001400041245015700055210006900212260000900281300001400290490000600304520175500310653001902065653003002084653003202114653001802146653001802164100001702182700001902199700001702218700002302235700002202258700003002280700001802310856012502328       2021                        eng d  a2574-096200aOne-dimensional multichannel g-C3N4.7 nanostructure realizing an efficient photocatalytic hydrogen evolution reaction and its theoretical investigations0 aOnedimensional multichannel gC3N47 nanostructure realizing an ef  cAPR   a3118-31290 v43 a<p>The emerging metal-free carbon nitride (C3N4) offers prominent possibilities for realizing the highly effective hydrogen evolution reaction (HER). However, its poor surface conductivity and insufficient catalytic sites hinder the HER performance. Herein, a one-dimensional vermicular rope-like graphitic carbon nitride nanostructure is demonstrated that consists of multichannel tubular pores and high nitrogen content, which is fabricated through a cost-effective approach having the final stoichiometry g-C3N4.7 for HER application. The present g-C3N4.7 is unique owing to the presence of abundant channels for the diffusion process, modulated surface chemistry with rich- electroactive sites from N-electron lone pairs, greatly reduced recombination rate of photoexcited exciton pairs, and a high donor concentration (4.26 x 10(17) cm(3)). The catalyst offers a visible-light-driven photocatalytic H-2 evolution rate as high as 4910 mu mol h(-1)g(-1) with an apparent quantum yield of 14.07% at band gap absorption (2.59 eV, 479 nm) under 7.68 mW cm(-2) illumination. The number of hydrogen gas molecules produced is 1.307 x 10(15) s(-1) cm(-2), which remained constant for a minimum of 18 h of repeated cycling in the HER without any degradation of the catalyst. In density functional theory calculations, a significant change in the band offset is observed due to N doping into the system in favor of electron catalysis. The theoretical band gap of a monolayer of g-C3N4.7 was enormously reduced because of the presence of additional densities of states from the doped N atom inside the band gap. These impurity or donor bands are formed inside the band gap region, which ultimately enhance the hydrogen ion reduction reaction enormously.</p>10acarbon nitride10aDensity functional theory10ahydrogen evolution reaction10anitrogen-rich10aPhotocatalyst1 aAntil, Bindu1 aKumar, Lakshya1 aRanjan, Ravi1 aShenoy, Sulakshana1 aTarafder, Kartick1 aGopinath, Chinnakonda, S.1 aDeka, Sasanka  uhttps://library.ncl.res.in/content/one-dimensional-multichannel-g-c3n47-nanostructure-realizing-efficient-photocatalytic