A sulfur self‐doped multifunctional biochar catalyst for overall water splitting and a supercapacitor from Camellia japonica flowers

Abstract

A versatile use of a sulfur self-doped biochar derived from Camellia japonica (camellia) flowers is demonstrated as a multifunctional catalyst for overall water splitting and a supercapacitor. The native sulfur content in the camellia flower facilitates in situ self-doping of sulfur, which highly activates the camellia-driven biochar (SA-Came) as a multifunctional catalyst with the enhanced electron-transfer ability and long-term durability. For water splitting, an SA-Came-based electrode is highly stable and shows reaction activities in both hydrogen and oxygen evolution reactions, with overpotentials of 154 and 362 mV at 10 mA cm −2 , respectively. For supercapacitors, SA-Came achieves a specific capacitance of 125.42 F g −1 at 2 A g −1 and high cyclic stability in a three-electrode system in a 1 M KOH electrolyte. It demonstrated a high energy density of 34.54 Wh kg −1 at a power density of 1600 W kg −1 as a symmetric hybrid supercapacitor device with a wide working potential range of 0-1.6 V.

Waste-Derived Catalysts for Water Electrolysis: Circular Economy-Driven Sustainable Green Hydrogen Energy

“…Xia et al prepared the S self-doped activated camellia (SA-Came) carbon nanospheres from camellia flowers through a hydrothermal treatment-pyrolysis route (Fig. 12a) [174].…”

Advances in Micro-/Mesopore Regulation Methods for Plant-Derived Carbon Materials

“…Gopalakrishnan et al [ 14 ] employed onion skin as a carbon precursor to synthesize heteroatom (N, P, S) co-doped porous carbon nanosheets via a carbonization and activation strategy. Xia et al [ 35 ] prepared a sulfur self-doped carbon material with Camellia japonica containing natural sulfur as a raw material and used it as an electrode material to achieve a specific capacitance of 125.42 F/g at a current density of 2 A/g. Gong et al [ 36 ] obtained porous carbon materials by using nitrogen-containing duckweed as a raw material with KOH activation.…”

“… Plants rich in heteroatoms: Elm Flower [ 37 ], Datura stramonium seed pods [ 20 ], bamboo [ 38 ], Pinecone [ 39 ], Durian peel [ 40 ], Rice husk [ 41 ], Peanut meal [ 42 ], Typha orientalis leaves [ 43 ], Lettuce slice [ 44 ], Soybean pods [ 45 ], Onion skin [ 14 ], Camellia japonica flowers [ 35 ], Duckweed [ 36 ], Hollyhock leaves [ 46 ], Cottonseed meal [ 47 ], Pomelo peel [ 48 ], Cherry flowers [ 49 ]. …”

Heteroatom-Doped Hierarchically Porous Biochar for Supercapacitor Application and Phenol Pollutant Remediation

“…Moreover, biochars are widely studied as electrode materials or catalysts because of their high specific surface area (SSA), adjustable pore structure, abundant surface heteroatom dopants, and good electrical conductivity [ 3 , 4 ]. A variety of biomasses have been converted into biochar materials for applications including electrochemical supercapacitors [ 5 , 6 , 7 , 8 ], electrosynthesis [ 9 , 10 ], and environmental remediation [ 11 , 12 , 13 ].…”

“…The following supporting information can be downloaded at: , Figure S1: EDX elemental mapping images of BC-24; Figure S2: Experimental and simulated Nyquist plots for the indicated electrodes; Figure S3: Cycling experiments for phenol degradation by the BC-24/PDS system; Table S1: The resistance parameters deduced from the equivalent circuits of EIS measurements; Table S2: Comparison of the capacitive performance of BC-24 in a three-electrode system with other biochar materials in the reported literature [ 6 , 20 , 61 , 62 , 63 , 64 , 65 , 66 , 67 ]; Table S3: Comparison of the catalytic phenol degradation performance of BC-24 through persulfate activation with reported literature [ 45 , 54 , 60 , 68 , 69 , 70 , 71 , 72 ].…”