Synthesis of lignin-derived nitrogen-doped carbon as a novel catalyst for 4-NP reduction evaluation

Abstract

In this study, nitrogen-doped carbon (NC) was fabricated using lignin as carbon source and g-C3N4 as sacrificial template and nitrogen source. The structural properties of as-prepared NC were characterized by TEM, XRD, FT-IR, Raman, XPS and BET techniques. Attractively, NC has proved efficient for reducing 4-nitrophenol (4-NP) to 4-aminophenol (4-AP) using NaBH4 as hydrogen donor with high apparent rate constant (kapp = 4.77 min−1) and specific mass activity (s = 361 mol kgcat−1 h−1), which values are superior to the previously reported catalysts in the literature. Density functional theory (DFT) calculations demonstrate that four kinds of N dopants can change the electronic structure of the adjacent carbon atoms and contribute to their catalytic properties dependant on N species, however, graphitic N species has much greater contribution to 4-NP adsorption and catalytic reduction. Furthermore, The preliminary mechanism of this transfer hydrogenation reaction over as-prepared NC is proposed on the basis of XPS and DFT data. Astoundingly, NC has excellent stability and reusability of six consecutive runs without loss of catalytic activity. These findings open up a vista to engineer lignin-derived NC as metal-free catalyst for hydrogenation reaction.

Sunlight driven photocatalytic degradation of organic pollutants using a MnV2O6/BiVO4 heterojunction: mechanistic perception and degradation pathways

“…another absorption peak at ~297 nm corresponding to 4-aminophenol (4-AP) with increasing intensity emerged. This outcome confirmed the comprehensive transformation of 4-NP to 4-AP without the production of intermediates as established in earlier reports also [39]. Absorbance and concentration of the solution are proportionate to each other and hence, absorbance A 0 (t=0) corresponds to initial concentration, and absorbance A t corresponds to the concentration at time t (C t ).…”

Nitrogen-doped lignin-derived carbon for catalytic reduction of hexavalent chromium via HCOOH-mediated hydrogenation

“…To explore the practical applications of N@C-g-C 3 N 4 -950, extended experiments were tested on the catalytic activities in other hydrogenation reactions of 4-NP, BPA and K 3 [Fe(CN) 6 ] using NaBH 4 as hydrogen donor. 13,28 For hydrogenation of nitrogroups, 4-NP can be completely reduced by N@C-g-C 3 N 4 -950 using NaBH 4 as hydrogen donor within 5 min (Fig. S15a†).…”

“…These carbon-based metal-free catalysts have been used for oxygen reduction reaction (ORR), oxygen evolution reaction (OER), hydrogen evolution reaction (HER) and 4-nitrophenol reduction so far. 11–13 It is generally considered that heteroatom dopants (N, P, S, B, etc. ) can improve the catalytic performance of carbon materials by changing the electronic structure of adjacent carbon and/or producing additional active sites.…”

“…52%). 13 The as-synthesized N@C-g-C 3 N 4 was characterized by TEM, HR-TEM, TGA, Raman, EDS-mapping, XPS and BET analysis. The as-obtained N@C-g-C 3 N 4 exhibits excellent catalytic activity in the HCOOH-mediated reduction of toxic Cr 6+ to benign Cr 3+ .…”

Collagen-Coated Superparamagnetic Iron Oxide Nanoparticles as a Sustainable Catalyst for Spirooxindole Synthesis

“…Natural polymers such as polysaccharides (cellulose, chitosan, chitin, alginate, carrageenan, lignin, fucoidan, etc.) and proteins have been used as catalysts in chemical transformations [12][13][14][15][16][17][18] . Coating magnetic particles with natural polymers allows them to use their functional groups for promoting chemical reactions and also easy separation 19,20 .…”