Bibliometric analysis of biochar research in 2021: a critical review for development, hotspots and trend directions

Abstract

As a bioproduct from the thermal decomposition of biomass, biochar has various applications in diversified field. In this study, a bibliometric analysis was conducted to visualize the current research status and trends of biochar research. A total of 5535 documents were collected from the Web of Science Core Collection and subjected to visualization analysis for the biochar field's development in 2021 with CiteSpace software. The visual analysis results demonstrate that the number of publications expanded dramatically in 2021, and the growth trend would continue. China and USA were the most contributing countries in biochar research in terms of the number of publications. Based on the keyword co-occurrence analyses, “Biochar for toxic metal immobilization”, “Biochar-based catalyst for biofuel production”, “Biochar for global climate change mitigation”, “Biochar for salinity and drought stress amelioration”, “Biochar amendment in composting”, and “Biochar as additives in anaerobic digestion” were the main research trends and hotspots in this field in 2021. This indicates that the biochar research was multidisciplinary. Regarding the research hotspots, the employment of biochar as heterogeneous catalysts for biofuel production gained great attention in 2021. On the contrary, bioremediation using functional bacteria immobilized on biochar and biochar-assisted advanced oxidation process were well-studied but with less frequency than other topics in 2021. Furthermore, the future research was proposed for green and sustainable applications of biochar. This review provides a comprehensive overview of the research frontiers, the evolution of research hotspots, and potential future research directions in the biochar field. Graphical Abstract

Facile Pyrolysis Treatment for the Synthesis of Single-Atom Mn Catalysts Derived from a Hyperaccumulator

“…15,16 It may be possible to consider hyperaccumulator biomass as a precursor material. 17 The distribution of both metals and major elements (including N, O, S, and P) in hyperaccumulator plants has been systematically investigated by several microprobe techniques. 18 As an example, Mn in the hyperaccumulators Gossia bidwillii and Virotia neurophylla was found to predominate as Mn(II) complexed with carboxylic acids, such as malate or citrate.…”

“…Benefiting from the lone pair of electrons, the doped heteroatoms in the carbon skeleton, including nitrogen (N), phosphorus (P), sulfur (S), and oxygen (O), exhibit strong coordination capacity with metal atoms. Among the various strategies for SAC preparation, the pyrolysis of metal–organic frameworks (MOFs), covalent–organic frameworks, and their derivatives is the most common method. , It may be possible to consider hyperaccumulator biomass as a precursor material . The distribution of both metals and major elements (including N, O, S, and P) in hyperaccumulator plants has been systematically investigated by several microprobe techniques .…”

Biochar amendment gradually immobilized soil As and Sb over 2 years

“…Among the various amendments capable of effectively passivating PTEs, biochar emerges as a highly promising option, offering a range of additional benefits beyond soil remediation (Bolan et al., 2022; Fang et al., 2023; Wu et al., 2023; Zhang, Wang, et al., 2023). These benefits include nutrient delivery, enhanced water retention, and long‐term carbon sequestration (Edeh et al., 2020; Guo et al., 2023; Li et al., 2023; Wang, Deng, et al., 2023).…”

Predicting the speciation of ionizable antibiotic ciprofloxacin by biochars with varying carbonization degrees

“… 16 Biochar's applications for global climate mitigation, salinity and drought stress amelioration, and biofuel production are also of great concern. 17 …”

“…16 Biochar's applications for global climate mitigation, salinity and drought stress amelioration, and biofuel production are also of great concern. 17 It has been reported that biochar can effectively sorb CIP and the precursor materials of biochar include rice straw, bagasse, sludge, bamboo, urban solid waste, marine algae, etc. 1,[18][19][20][21] However, report on CIP sorption by biochar derived from woodchip, a biomass with high content of lignin and cellulose, is rare.…”